Build a Picture from Simple Shapes - Practice 1
A drawing can combine simple shapes into an imagined object.
Drawing and artca1a4
Learn it. Try it. Make it yours.
Worksheets
Number puzzles, historical clues, rocks and planets, reading discoveries, map skills, and poetry. Practice online or take a printed copy along.
1072 worksheets
Build a Picture from Simple Shapes - Practice 2
A drawing can combine simple shapes into an imagined object.
Drawing and artca1a5
Build a Picture from Shapes
Use simple shapes as a starting plan, then turn them into your own drawing.
Drawing and artca290
Show Depth with Overlapping Shapes - Practice 1
In a simple opaque-shape drawing, the visible shape that hides part of another is in front.
Drawing and artca2a8
Show Depth with Overlapping Shapes - Practice 2
In a simple opaque-shape drawing, the visible shape that hides part of another is in front.
Drawing and artca2a9
Plan a Repeating Picture Border - Practice 1
Find the repeating unit before counting decorations.
Drawing and artca2aa
Plan a Repeating Picture Border - Practice 2
Find the repeating unit before counting decorations.
Drawing and artca2ab
Reflect a Mark across a Vertical Line - Practice 1
A reflected mark is the same horizontal distance on the other side of the mirror line.
Drawing and artca3ac
Reflect a Mark across a Vertical Line - Practice 2
A reflected mark is the same horizontal distance on the other side of the mirror line.
Drawing and artca3ad
Notice the Space around a Shape - Practice 1
Positive space is the selected subject area; negative space is the area around or between those subjects.
Drawing and artca4ag
Notice the Space around a Shape - Practice 2
Positive space is the selected subject area; negative space is the area around or between those subjects.
Drawing and artca4ah
Keep Proportions when Enlarging a Design - Practice 1
Multiply every length by the same factor to keep proportions in a flat design.
Drawing and artca5ak
Keep Proportions when Enlarging a Design - Practice 2
Multiply every length by the same factor to keep proportions in a flat design.
Drawing and artca5al
Use Value and Overlap for Depth
Plan a simple still life with light, dark and overlapping shapes.
Drawing and artca690
Order a Labeled Value Scale - Practice 1
Value means lightness or darkness, not the cost or quality of an artwork.
Drawing and artca6ao
Order a Labeled Value Scale - Practice 2
Value means lightness or darkness, not the cost or quality of an artwork.
Drawing and artca6ap
Use One-Point Perspective as a Drawing Model - Practice 1
In a simple one-point perspective view facing a box front, edges receding perpendicular to the picture plane converge toward one vanishing point.
Drawing and artca7as
Use One-Point Perspective as a Drawing Model - Practice 2
In a simple one-point perspective view facing a box front, edges receding perpendicular to the picture plane converge toward one vanishing point.
Drawing and artca7at
Distinguish Flat Shapes from Solid Forms - Practice 1
A shape is two-dimensional; a form has three-dimensional extent.
Drawing and artca7au
Distinguish Flat Shapes from Solid Forms - Practice 2
A shape is two-dimensional; a form has three-dimensional extent.
Drawing and artca7av
Keep a Thumbnail Aspect Ratio - Practice 1
An aspect ratio compares width to height.
Drawing and artca8aw
Keep a Thumbnail Aspect Ratio - Practice 2
An aspect ratio compares width to height.
Drawing and artca8ax
Account for Positive and Negative Area - Practice 1
In these ideal flat designs, positive and negative regions cover the whole frame without overlap or gaps.
Drawing and artca9b0
Account for Positive and Negative Area - Practice 2
In these ideal flat designs, positive and negative regions cover the whole frame without overlap or gaps.
Drawing and artca9b1
Choose a Focal Treatment for a Stated Brief - Practice 1
A focal area can be emphasized through contrast, placement, scale or isolation.
Drawing and artca9b2
Choose a Focal Treatment for a Stated Brief - Practice 2
A focal area can be emphasized through contrast, placement, scale or isolation.
Drawing and artca9b3
Transfer a Design between Proportional Grids - Practice 1
A grid can help transfer locations without tracing an existing artwork.
Drawing and artcaab4
Transfer a Design between Proportional Grids - Practice 2
A grid can help transfer locations without tracing an existing artwork.
Drawing and artcaab5
Make a Visual Message Work without Color Alone - Practice 1
A message should not depend on color alone when the same information can be given by labels, patterns or symbols.
Drawing and artcaab6
Make a Visual Message Work without Color Alone - Practice 2
A message should not depend on color alone when the same information can be given by labels, patterns or symbols.
Drawing and artcaab7
Plan Time across Storyboard Panels - Practice 1
A storyboard can attach a duration to each planned shot.
Drawing and artcabb8
Plan Time across Storyboard Panels - Practice 2
A storyboard can attach a duration to each planned shot.
Drawing and artcabb9
Plan a Labeled Safe Area inside a Print - Practice 1
In this paper layout model, a required inset margin is measured inward from each trim edge.
Drawing and artcabba
Plan a Labeled Safe Area inside a Print - Practice 2
In this paper layout model, a required inset margin is measured inward from each trim edge.
Drawing and artcabbb
Write an Honest Caption for a Visual Work - Practice 1
A caption should distinguish observation, interpretation and invention.
Drawing and artcacbc
Write an Honest Caption for a Visual Work - Practice 2
A caption should distinguish observation, interpretation and invention.
Drawing and artcacbd
Keep a Designed Chart Faithful to Its Data - Practice 1
Graphic choices can change the impression of data.
Drawing and artcacbe
Keep a Designed Chart Faithful to Its Data - Practice 2
Graphic choices can change the impression of data.
Drawing and artcacbf
Explore Straight, Curved and Zigzag Lines - Practice 1
An adult can read the clues aloud.
Drawing and artcaka0
Explore Straight, Curved and Zigzag Lines - Practice 2
An adult can read the clues aloud.
Drawing and artcaka1
Play with Straight and Curved Lines - Practice 1
Point, talk, and try with a trusted adult.
Drawing and artcap0l
Play with Straight and Curved Lines - Practice 2
Point, talk, and try with a trusted adult.
Drawing and artcap0m
Build a Picture with Shapes - Practice 1
Point, talk, and try with a trusted adult.
Drawing and artcap0n
Build a Picture with Shapes - Practice 2
Point, talk, and try with a trusted adult.
Drawing and artcap0o
Colors Have Names and Shades
Match labels, spot lighter and darker shades, and make your own labeled picture.
Colors and combinationscc190
Sort Colors with a Stated Palette Key - Practice 1
For this art palette, red, orange and yellow are called warm; blue, green and violet are called cool.
Colors and combinationscc1a6
Sort Colors with a Stated Palette Key - Practice 2
For this art palette, red, orange and yellow are called warm; blue, green and violet are called cool.
Colors and combinationscc1a7
Separate Tints and Shades in a Paint Model - Practice 1
In this simplified paint vocabulary, adding white makes a tint and adding black makes a shade.
Colors and combinationscc3ae
Separate Tints and Shades in a Paint Model - Practice 2
In this simplified paint vocabulary, adding white makes a tint and adding black makes a shade.
Colors and combinationscc3af
Count a Deliberately Limited Palette - Practice 1
A limited palette restricts the number of distinct color choices.
Colors and combinationscc4ai
Count a Deliberately Limited Palette - Practice 2
A limited palette restricts the number of distinct color choices.
Colors and combinationscc4aj
Light Mixing Is Not Paint Mixing
Compare colored light, printed ink and value without treating them as the same process.
Colors and combinationscc590
Compare Additive Colored-Light Mixtures - Practice 1
In this ideal RGB light model, red plus green gives yellow, green plus blue gives cyan, and blue plus red gives magenta.
Colors and combinationscc5am
Compare Additive Colored-Light Mixtures - Practice 2
In this ideal RGB light model, red plus green gives yellow, green plus blue gives cyan, and blue plus red gives magenta.
Colors and combinationscc5an
Separate Hue, Value and Intensity - Practice 1
Hue names a color family, value describes lightness, and intensity or saturation describes vividness in this art vocabulary.
Colors and combinationscc6aq
Separate Hue, Value and Intensity - Practice 2
Hue names a color family, value describes lightness, and intensity or saturation describes vividness in this art vocabulary.
Colors and combinationscc6ar
Use Opposite Pairs on a Given Color Wheel - Practice 1
This traditional six-hue RYB art wheel pairs red with green, yellow with violet, and blue with orange.
Colors and combinationscc8ay
Use Opposite Pairs on a Given Color Wheel - Practice 2
This traditional six-hue RYB art wheel pairs red with green, yellow with violet, and blue with orange.
Colors and combinationscc8az
Match Colors with Their Written Labels - Practice 1
Read the labels with an adult.
Colors and combinationsccka2
Match Colors with Their Written Labels - Practice 2
Read the labels with an adult.
Colors and combinationsccka3
Choose the Sense Named by a Detail - Practice 1
Sensory details can describe what a character sees, hears, smells, tastes or feels by touch.
Descriptive writingcd1bo
Choose the Sense Named by a Detail - Practice 2
Sensory details can describe what a character sees, hears, smells, tastes or feels by touch.
Descriptive writingcd1bp
Choose Details a Reader Can Sense
Replace broad words with concrete sights, sounds, and textures.
Descriptive writingcd201
Choose a Verb for the Action You Mean - Practice 1
A precise verb can show how an action happens.
Descriptive writingcd2bu
Choose a Verb for the Action You Mean - Practice 2
A precise verb can show how an action happens.
Descriptive writingcd2bv
Choose Precise Story Details
Practice turning vague descriptions into clear images.
Descriptive writingcd301
Let Dialogue Do a Particular Job - Practice 1
Dialogue can ask, warn, offer, refuse or reveal information.
Descriptive writingcd3c0
Let Dialogue Do a Particular Job - Practice 2
Dialogue can ask, warn, offer, refuse or reveal information.
Descriptive writingcd3c1
Revise with Precise Verbs
Choose verbs that communicate a specific action or tone.
Descriptive writingcd401
Choose Details That Match a Scene
Use specific sounds, sights and actions to create a consistent mood.
Descriptive writingcd402
Replace a General Description with a Concrete Detail - Practice 1
Concrete detail gives something a reader can picture or otherwise sense.
Descriptive writingcd5cc
Replace a General Description with a Concrete Detail - Practice 2
Concrete detail gives something a reader can picture or otherwise sense.
Descriptive writingcd5cd
Suggest Emotion through Action without Claiming Certainty - Practice 1
Actions can suggest a fictional character's emotion, but a gesture alone does not diagnose a real person.
Descriptive writingcd6ci
Suggest Emotion through Action without Claiming Certainty - Practice 2
Actions can suggest a fictional character's emotion, but a gesture alone does not diagnose a real person.
Descriptive writingcd6cj
Choose Figurative Language for a Purpose
Use comparisons that support a specific image or feeling.
Descriptive writingcd701
Choose Details That Serve a Scene Focus - Practice 1
Description selects rather than records everything.
Descriptive writingcd8cu
Choose Details That Serve a Scene Focus - Practice 2
Description selects rather than records everything.
Descriptive writingcd8cv
Separate Spoken Words from a Possible Subtext - Practice 1
Subtext is an implied meaning beyond literal words.
Descriptive writingcd9d0
Separate Spoken Words from a Possible Subtext - Practice 2
Subtext is an implied meaning beyond literal words.
Descriptive writingcd9d1
Develop a Motif as Its Meaning Changes
Plan recurring imagery that evolves with a character rather than merely repeating.
Descriptive writingcdb01
Fit Narrative Voice to a Stated Register - Practice 1
Voice includes choices of vocabulary, rhythm and perspective.
Descriptive writingcdbdc
Fit Narrative Voice to a Stated Register - Practice 2
Voice includes choices of vocabulary, rhythm and perspective.
Descriptive writingcdbdd
Dialogue, Subtext, and Competing Intentions
Revise a conversation so action and omission carry meaning.
Descriptive writingcdd01
Find the Setting in a Short Scene - Practice 1
Read the sentence with an adult.
Descriptive writingcdkbi
Find the Setting in a Short Scene - Practice 2
Read the sentence with an adult.
Descriptive writingcdkbj
Try Words That Suggest Sounds - Practice 1
A sound word imitates or suggests a sound, such as tap or buzz.
Poetryco1bq
Try Words That Suggest Sounds - Practice 2
A sound word imitates or suggests a sound, such as tap or buzz.
Poetryco1br
Hear Rhyme and Notice Poem Lines
Listen to a short original poem and notice its sounds.
Poetryco201
Listen for Matching Ending Sounds - Practice 1
Rhyme concerns sounds, not just spelling.
Poetryco2bw
Listen for Matching Ending Sounds - Practice 2
Rhyme concerns sounds, not just spelling.
Poetryco2bx
Explain the Shared Feature in a Simile - Practice 1
A simile compares unlike things using words such as like or as.
Poetryco4c6
Explain the Shared Feature in a Simile - Practice 2
A simile compares unlike things using words such as like or as.
Poetryco4c7
Use Sound and Personification in Poetry
Identify sound patterns and human qualities given to nonhuman things.
Poetryco501
Plan Lines in Stanza Groups - Practice 1
A stanza is a group of lines in a poem, often separated from other groups by space.
Poetryco5ce
Plan Lines in Stanza Groups - Practice 2
A stanza is a group of lines in a poem, often separated from other groups by space.
Poetryco5cf
Read a Metaphor without Making It Literal - Practice 1
A metaphor presents one thing through another to suggest a connection.
Poetryco7co
Read a Metaphor without Making It Literal - Practice 2
A metaphor presents one thing through another to suggest a connection.
Poetryco7cp
Notice What a Line Break Leaves at the Edge - Practice 1
A line break controls where a poetic line ends, even when the sentence continues.
Poetryco8cw
Notice What a Line Break Leaves at the Edge - Practice 2
A line break controls where a poetic line ends, even when the sentence continues.
Poetryco8cx
Use Line Breaks to Shape Expectation
Analyze how a line ending can delay or revise a reader's interpretation.
Poetryco901
Keep an Extended Metaphor Coherent - Practice 1
An extended metaphor develops a comparison across several related details.
Poetrycoad6
Keep an Extended Metaphor Coherent - Practice 2
An extended metaphor develops a comparison across several related details.
Poetrycoad7
Use a Chosen Poetic Constraint Deliberately - Practice 1
A formal constraint can support invention without defining all poetry.
Poetrycocdi
Use a Chosen Poetic Constraint Deliberately - Practice 2
A formal constraint can support invention without defining all poetry.
Poetrycocdj
Edit Poetic Variants with an Explicit Rationale
Build a small critical apparatus without erasing uncertainty.
Poetrycoe01
Give a Character a Clear Want - Practice 1
A goal tells what a character wants to do or obtain.
Story planningcp1bm
Give a Character a Clear Want - Practice 2
A goal tells what a character wants to do or obtain.
Story planningcp1bn
Build a Clear Story Plan
Choose a character, goal, problem, and helpful action.
Story planningcp201
Put an Obstacle between a Character and a Goal - Practice 1
An obstacle makes a goal harder to reach.
Story planningcp2bs
Put an Obstacle between a Character and a Goal - Practice 2
An obstacle makes a goal harder to reach.
Story planningcp2bt
Creativity Planner
Plan a setting, character, goal, problem, and change.
Story planningcp301
Give a Character a Goal and a Choice
Connect a story problem with an action that can address it.
Story planningcp302
Choose a Narrator Position - Practice 1
First-person narration uses I or we for the narrator's own experience.
Story planningcp4c4
Choose a Narrator Position - Practice 2
First-person narration uses I or we for the narrator's own experience.
Story planningcp4c5
Plant a Clue and Pay It Off
Connect an early story detail to a later solution.
Story planningcp501
Plan a Scene from One Viewpoint
Decide what a viewpoint character can observe, think and infer.
Story planningcp502
Connect a Character Choice to Its Consequence - Practice 1
A choice can change a situation and reveal priorities.
Story planningcp5ca
Connect a Character Choice to Its Consequence - Practice 2
A choice can change a situation and reveal priorities.
Story planningcp5cb
Support a Character Choice with a Motive - Practice 1
A believable motive connects a character's desire, knowledge and situation to a choice.
Story planningcp7cm
Support a Character Choice with a Motive - Practice 2
A believable motive connects a character's desire, knowledge and situation to a choice.
Story planningcp7cn
Connect Motivation, Conflict, and Choice
Plan a consequential decision around competing character goals.
Story planningcp801
Prepare a Later Event with an Earlier Detail - Practice 1
Foreshadowing can plant a relevant detail before it matters.
Story planningcp8cs
Prepare a Later Event with an Earlier Detail - Practice 2
Foreshadowing can plant a relevant detail before it matters.
Story planningcp8ct
Test a Narrator Claim against Story Evidence - Practice 1
A narrator's account can be incomplete, mistaken or deliberately misleading.
Story planningcp9cy
Test a Narrator Claim against Story Evidence - Practice 2
A narrator's account can be incomplete, mistaken or deliberately misleading.
Story planningcp9cz
Use Parallel Scenes to Make Change Visible - Practice 1
Parallel scenes repeat a situation or image with meaningful differences.
Story planningcpbda
Use Parallel Scenes to Make Change Visible - Practice 2
Parallel scenes repeat a situation or image with meaningful differences.
Story planningcpbdb
Compare Interpretations without Erasing Ambiguity - Practice 1
A text can support more than one interpretation.
Story planningcpcdg
Compare Interpretations without Erasing Ambiguity - Practice 2
A text can support more than one interpretation.
Story planningcpcdh
Focalization and the Limits of Narrative Knowledge
Revise a scene by controlling access to perception and thought.
Story planningcpd01
Design a Constraint-Led Narrative Inquiry
Use controlled revision and reflective analysis in creative research.
Story planningcpe01
Choose a Character, Place, and Goal
Build the first pieces of a story with a read-aloud activity.
Story planningcpk01
Find Who Is Acting in a Story - Practice 1
An adult can read each short fictional sentence aloud.
Story planningcpkbg
Find Who Is Acting in a Story - Practice 2
An adult can read each short fictional sentence aloud.
Story planningcpkbh
Build a Beginning, Middle, and Ending
Arrange connected story events in a clear order.
Story sequencecs101
Connect Actions with Because and So
Make a story's causes and results easy to follow.
Story sequencecs201
Connect a Goal, Problem, and Ending
Make story events connect through cause and effect.
Story sequencecs301
Connect Story Events through Cause - Practice 1
A cause helps explain why something happens in a story.
Story sequencecs3by
Connect Story Events through Cause - Practice 2
A cause helps explain why something happens in a story.
Story sequencecs3bz
Preserve a Stated Story Dependency - Practice 1
Some story events depend on earlier ones.
Story sequencecs4c8
Preserve a Stated Story Dependency - Practice 2
Some story events depend on earlier ones.
Story sequencecs4c9
Choose Scene or Summary for a Pacing Goal - Practice 1
A scene can slow down to show actions and dialogue moment by moment.
Story sequencecs6cg
Choose Scene or Summary for a Pacing Goal - Practice 2
A scene can slow down to show actions and dialogue moment by moment.
Story sequencecs6ch
Control Narrative Pace with Scene and Summary
Decide which moments to expand and which to compress.
Story sequencecsa01
Distinguish Event Order from Telling Order - Practice 1
Narrative order can differ from chronological order.
Story sequencecsad4
Distinguish Event Order from Telling Order - Practice 2
Narrative order can differ from chronological order.
Story sequencecsad5
Order Three Story Pictures - Practice 1
An adult can read the picture captions aloud.
Story sequencecskbk
Order Three Story Pictures - Practice 2
An adult can read the picture captions aloud.
Story sequencecskbl
Revise for One Observable Goal - Practice 1
A useful revision goal names a change you can inspect in the draft.
Writing goalscw3c2
Revise for One Observable Goal - Practice 2
A useful revision goal names a change you can inspect in the draft.
Writing goalscw3c3
Creative Writing Goals
Choose a writing goal and a practical revision step.
Writing goalscw401
Turn Revision Goals into Specific Changes
Match a writing goal to a concrete revision and a way to check it.
Writing goalscw601
Revise for Clarity Without Changing the Facts
Choose edits that clarify a draft while preserving its meaning.
Writing goalscw602
Turn a Broad Writing Aim into a Concrete Step - Practice 1
A process goal identifies a doable action and a way to check it.
Writing goalscw6ck
Turn a Broad Writing Aim into a Concrete Step - Practice 2
A process goal identifies a doable action and a way to check it.
Writing goalscw6cl
Keep a Limited Viewpoint within Its Knowledge - Practice 1
A limited viewpoint stays with what the selected character can perceive, remember or reasonably infer.
Writing goalscw7cq
Keep a Limited Viewpoint within Its Knowledge - Practice 2
A limited viewpoint stays with what the selected character can perceive, remember or reasonably infer.
Writing goalscw7cr
Revise Paragraphs for Coherence
Align order, transitions, and references with a paragraph's central movement.
Writing goalscw901
Connect an Ending to What Came Before - Practice 1
An ending can resolve, complicate or leave open a central question.
Writing goalscw9d2
Connect an Ending to What Came Before - Practice 2
An ending can resolve, complicate or leave open a central question.
Writing goalscw9d3
Choose the Right Level of Revision - Practice 1
Revision can change structure, scene content or sentence wording.
Writing goalscwad8
Choose the Right Level of Revision - Practice 2
Revision can change structure, scene content or sentence wording.
Writing goalscwad9
Give Feedback a Writer Can Act On - Practice 1
Useful feedback names a place in the draft, describes an effect and connects a suggestion to the writer's stated goal.
Writing goalscwbde
Give Feedback a Writer Can Act On - Practice 2
Useful feedback names a place in the draft, describes an effect and connects a suggestion to the writer's stated goal.
Writing goalscwbdf
Plan a Revision That Preserves Deliberate Ambiguity
Distinguish a productive unanswered question from missing causal information.
Writing goalscwc01
Support a Creative Reflection with Draft Evidence - Practice 1
A useful portfolio reflection connects an intention, a change and evidence in the work.
Writing goalscwcdk
Support a Creative Reflection with Draft Evidence - Practice 2
A useful portfolio reflection connects an intention, a change and evidence in the work.
Writing goalscwcdl
Documentary Writing and Transparent Reconstruction
Develop an editorial method for combining evidence and invention.
Writing goalscwe01
Separate Weather from Climate Descriptions - Practice 1
Weather describes conditions over a short time.
Weather and climategc2ag
Separate Weather from Climate Descriptions - Practice 2
Weather describes conditions over a short time.
Weather and climategc2ah
Weather or Climate?
Distinguish today's conditions from long-term patterns.
Weather and climategc301
Forecast detectives
Use place, time, temperature, wind, and rain chances to make a plan.
Weather and climategc310
Follow an echo
Use radar legends and time sequences without treating colors as promises.
Weather and climategc311
Read Weather Tables Without Overclaiming
Compare daily weather while distinguishing it from climate.
Weather and climategc401
Total a Rainfall Record - Practice 1
Rainfall depths measured over non-overlapping periods can be added when they use the same location and units.
Weather and climategc4aq
Total a Rainfall Record - Practice 2
Rainfall depths measured over non-overlapping periods can be added when they use the same location and units.
Weather and climategc4ar
Compare Long-Term Climate Averages
Read temperature averages without confusing them with a daily forecast.
Weather and climategc502
Rain chances are not timers
Use place, time, temperature, wind, and rain chances to make a plan.
Weather and climategc510
Radar is a measurement
Use radar legends and time sequences without treating colors as promises.
Weather and climategc511
Compare a Value with a Climate Reference - Practice 1
A climate normal is a reference statistic for a stated period; standard normals commonly use 30 years.
Weather and climategc6b4
Compare a Value with a Climate Reference - Practice 2
A climate normal is a reference statistic for a stated period; standard normals commonly use 30 years.
Weather and climategc6b5
Compare Seasonal Climate Patterns
Compare selected monthly averages without treating them as daily forecasts.
Weather and climategc801
Evaluate a forecast
Use place, time, temperature, wind, and rain chances to make a plan.
Weather and climategc810
Radar limits and evidence
Use radar legends and time sequences without treating colors as promises.
Weather and climategc811
Separate Climate Emulator Sensitivity from Attribution
Analyze interactions in a stated model without overclaiming causation.
Weather and climategce01
Follow the Compass
Use north, south, east, and west on a simple map.
Directionsgd101
Find Opposite Compass Directions - Practice 1
On a compass rose, north is opposite south and east is opposite west.
Directionsgd1a6
Find Opposite Compass Directions - Practice 2
On a compass rose, north is opposite south and east is opposite west.
Directionsgd1a7
Plan a Route with Compass Directions
Track a journey one direction at a time.
Directionsgd201
Meet the compass
Read a compass, follow a bearing, and understand two kinds of north.
Directionsgd310
Turn around a Compass Rose - Practice 1
For a north-up compass rose, clockwise quarter turns go north, east, south, west.
Directionsgd3ak
Turn around a Compass Rose - Practice 2
For a north-up compass rose, clockwise quarter turns go north, east, south, west.
Directionsgd3al
Use a Stated Clock Offset - Practice 1
These are fictional clock-offset puzzles, not real time-zone rules.
Directionsgd4as
Use a Stated Clock Offset - Practice 2
These are fictional clock-offset puzzles, not real time-zone rules.
Directionsgd4at
Follow a bearing
Read a compass, follow a bearing, and understand two kinds of north.
Directionsgd510
Magnetic and true north
Read a compass, follow a bearing, and understand two kinds of north.
Directionsgd810
Relate Longitude to Ideal Solar Time - Practice 1
In an ideal mean-solar-time model, 360 degrees corresponds to 24 hours, or 15 degrees per hour.
Directionsgdabo
Relate Longitude to Ideal Solar Time - Practice 2
In an ideal mean-solar-time model, 360 degrees corresponds to 24 hours, or 15 degrees per hour.
Directionsgdabp
Describe Places Near and Between
Use location words to describe a familiar place.
Directionsgdk01
Find a Place beside Another Place - Practice 1
An adult can read these clues aloud.
Directionsgdka0
Find a Place beside Another Place - Practice 2
An adult can read these clues aloud.
Directionsgdka1
In, On, or Under? - Practice 1
Point, talk, and try with a trusted adult.
Directionsgdp0d
In, On, or Under? - Practice 2
Point, talk, and try with a trusted adult.
Directionsgdp0e
Read a Map Grid Address - Practice 1
This grid names columns with letters and rows with numbers.
Grid maps and scalegg2ac
Read a Map Grid Address - Practice 2
This grid names columns with letters and rows with numbers.
Grid maps and scalegg2ad
Add the Parts of a Route - Practice 1
A route can bend.
Grid maps and scalegg2ae
Add the Parts of a Route - Practice 2
A route can bend.
Grid maps and scalegg2af
Find Places on a Neighborhood Grid
Use lettered columns, numbered rows and simple directions.
Grid maps and scalegg302
Convert Map Length to Ground Distance - Practice 1
Multiply the stated map length by the ground distance represented by one map unit.
Grid maps and scalegg3ai
Convert Map Length to Ground Distance - Practice 2
Multiply the stated map length by the ground distance represented by one map unit.
Grid maps and scalegg3aj
Locate North and South of the Equator - Practice 1
Latitude measures position north or south of the equator.
Grid maps and scalegg3am
Locate North and South of the Equator - Practice 2
Latitude measures position north or south of the equator.
Grid maps and scalegg3an
Use Grid References and Scale
Locate places and turn map distances into real distances.
Grid maps and scalegg401
Plan a Route Using Map Distances
Convert printed route lengths into real distances.
Grid maps and scalegg402
Locate East and West of Greenwich - Practice 1
Longitude is measured east or west from the prime meridian through Greenwich.
Grid maps and scalegg4ao
Locate East and West of Greenwich - Practice 2
Longitude is measured east or west from the prime meridian through Greenwich.
Grid maps and scalegg4ap
Convert Map Scale into Real Distance
Multiply map measurements by a distance scale.
Grid maps and scalegg501
Calculate Average Population Density - Practice 1
Average population density equals people divided by area.
Grid maps and scalegg5au
Calculate Average Population Density - Practice 2
Average population density equals people divided by area.
Grid maps and scalegg5av
Read Latitude and Longitude
Use the equator and prime meridian to interpret coordinates.
Grid maps and scalegg601
Compare Two Maps of the Same Route
Use two scales to check that a real distance stays the same.
Grid maps and scalegg602
Read a Ratio Scale - Practice 1
A scale of 1:N compares equal units.
Grid maps and scalegg6b2
Read a Ratio Scale - Practice 2
A scale of 1:N compares equal units.
Grid maps and scalegg6b3
Convert a Representative Map Scale
Translate a unitless scale ratio into real-world distances.
Grid maps and scalegg701
Compare Counts with Rates on a Map - Practice 1
A count map and a rate map answer different questions.
Grid maps and scalegg7b6
Compare Counts with Rates on a Map - Practice 2
A count map and a rate map answer different questions.
Grid maps and scalegg7b7
Express a Regional Rate per Thousand - Practice 1
A rate per 1,000 equals count divided by population, multiplied by 1,000.
Grid maps and scalegg7b8
Express a Regional Rate per Thousand - Practice 2
A rate per 1,000 equals count divided by population, multiplied by 1,000.
Grid maps and scalegg7b9
Find the Smaller Longitude Separation - Practice 1
Use east longitudes as positive and west as negative.
Grid maps and scalegg8bc
Find the Smaller Longitude Separation - Practice 2
Use east longitudes as positive and west as negative.
Grid maps and scalegg8bd
Combine Regions before Finding Density - Practice 1
For a combined population density, add populations and add areas, then divide.
Grid maps and scalegg8be
Combine Regions before Finding Density - Practice 2
For a combined population density, add populations and add areas, then divide.
Grid maps and scalegg8bf
Choose a Map Projection by Purpose - Practice 1
Flattening the curved Earth requires tradeoffs.
Grid maps and scalegg9bi
Choose a Map Projection by Purpose - Practice 2
Flattening the curved Earth requires tradeoffs.
Grid maps and scalegg9bj
Bound a Difference between Map Coordinates - Practice 1
When each coordinate has a stated maximum absolute error, a conservative bound on their difference is the sum of those error bounds.
Grid maps and scalegg9bk
Bound a Difference between Map Coordinates - Practice 2
When each coordinate has a stated maximum absolute error, a conservative bound on their difference is the sum of those error bounds.
Grid maps and scalegg9bl
Separate Net Migration from Total Movement - Practice 1
Net migration is arrivals minus departures over the same boundary and period.
Grid maps and scalegg9bm
Separate Net Migration from Total Movement - Practice 2
Net migration is arrivals minus departures over the same boundary and period.
Grid maps and scalegg9bn
Read a Thematic Map Class Boundary - Practice 1
A legend must say which class owns a boundary value.
Grid maps and scaleggabq
Read a Thematic Map Class Boundary - Practice 2
A legend must say which class owns a boundary value.
Grid maps and scaleggabr
Square a Linear Scale for Area - Practice 1
If all linear dimensions are multiplied by k, area is multiplied by k squared.
Grid maps and scaleggabs
Square a Linear Scale for Area - Practice 2
If all linear dimensions are multiplied by k, area is multiplied by k squared.
Grid maps and scaleggabt
Interpret Population Density Across Areas
Calculate densities and avoid misleading comparisons of aggregated regions.
Grid maps and scaleggb01
Weight a Survey by the Represented Population - Practice 1
Equal sample sizes do not make regions equally populous.
Grid maps and scaleggbbu
Weight a Survey by the Represented Population - Practice 2
Equal sample sizes do not make regions equally populous.
Grid maps and scaleggbbv
Use the Eligible Population Denominator - Practice 1
A rate must match the question.
Grid maps and scaleggbbw
Use the Eligible Population Denominator - Practice 2
A rate must match the question.
Grid maps and scaleggbbx
Choose the Baseline for Percent Change - Practice 1
Percent change uses the earlier value as denominator: (later - earlier) / earlier x 100.
Grid maps and scaleggbby
Choose the Baseline for Percent Change - Practice 2
Percent change uses the earlier value as denominator: (later - earlier) / earlier x 100.
Grid maps and scaleggbbz
Evaluate a Spatial Site-Selection Model
Apply constraints and weighted criteria, then test how assumptions affect a choice.
Grid maps and scaleggc01
Avoid Guessing Individual Traits from Regional Data - Practice 1
A regional association is not automatically an individual association.
Grid maps and scaleggcc0
Avoid Guessing Individual Traits from Regional Data - Practice 2
A regional association is not automatically an individual association.
Grid maps and scaleggcc1
See How Grouping Changes Regional Summaries - Practice 1
Combining small areas can change reported regional averages even when no underlying observations change.
Grid maps and scaleggcc2
See How Grouping Changes Regional Summaries - Practice 2
Combining small areas can change reported regional averages even when no underlying observations change.
Grid maps and scaleggcc3
Keep Missing Measurements Separate from Zero - Practice 1
Missing is not zero.
Grid maps and scaleggcc4
Keep Missing Measurements Separate from Zero - Practice 2
Missing is not zero.
Grid maps and scaleggcc5
Aggregation, Denominators, and Ecological Inference
Interpret regional rates without attributing them to individuals.
Grid maps and scaleggd01
Validate Spatial Predictions for Their Intended Use
Design cross-validation that matches geographic deployment.
Grid maps and scalegge01
Ordinary Kriging as Constrained Prediction
Derive two-site kriging weights from a stated covariance model.
Grid maps and scalegge02
Name Landforms from Their Shapes - Practice 1
Use the stated landform clue.
Landformsgl1aa
Name Landforms from Their Shapes - Practice 2
Use the stated landform clue.
Landformsgl1ab
Describe Land and Water
Match landform names to their defining features.
Landformsgl201
Distinguish Islands, Peninsulas, and Valleys
Classify landforms using their defining features.
Landformsgl301
Compare Heights above the Same Datum - Practice 1
Elevation is height relative to a specified reference level, or datum.
Landformsgl5aw
Compare Heights above the Same Datum - Practice 2
Elevation is height relative to a specified reference level, or datum.
Landformsgl5ax
Trace a River Network Downstream - Practice 1
Read arrows as downstream flow in this simplified river network.
Landformsgl5ay
Trace a River Network Downstream - Practice 2
Read arrows as downstream flow in this simplified river network.
Landformsgl5az
Calculate a Land-Cover Percentage - Practice 1
A land-cover percentage compares the area of a stated cover type with the full mapped area.
Landformsgl8bg
Calculate a Land-Cover Percentage - Practice 2
A land-cover percentage compares the area of a stated cover type with the full mapped area.
Landformsgl8bh
Trace Drainage Through a Watershed
Use slope, stream connections, and divides to reason about runoff.
Landformsgl901
Sort Land and Water Clues - Practice 1
Read with an adult.
Landformsglka4
Sort Land and Water Clues - Practice 2
Read with an adult.
Landformsglka5
Match Places to Their Map Symbols - Practice 1
Read all three entries in the supplied map legend.
Map symbolsgm1a8
Match Places to Their Map Symbols - Practice 2
Read all three entries in the supplied map legend.
Map symbolsgm1a9
Read a Map Key
Use a key to connect symbols with places.
Map symbolsgm201
Choose and Read Map Symbols
Use a legend instead of guessing what a symbol means.
Map symbolsgm301
Choose a Map Projection for a Purpose
Evaluate what a world map preserves and what it distorts.
Map symbolsgma01
Raster Aggregation and the Meaning of a Cell
Choose aggregation rules that preserve the quantity a map represents.
Map symbolsgmd01
Use a Simple Map Key - Practice 1
A map key explains what a symbol means on that map.
Map symbolsgmka2
Use a Simple Map Key - Practice 2
A map key explains what a symbol means on that map.
Map symbolsgmka3
Follow a Picture Route - Practice 1
Point, talk, and try with a trusted adult.
Map symbolsgmp0f
Follow a Picture Route - Practice 2
Point, talk, and try with a trusted adult.
Map symbolsgmp0g
Count countries with a rule
Learn a common country count and the rule behind it.
Countries and territoriesgn310
Countries and territories
Learn a common country count and the rule behind it.
Countries and territoriesgn510
Ask What a Country Count Includes - Practice 1
A country count depends on the definition, reference date and treatment of territories or recognition.
Countries and territoriesgn6b0
Ask What a Country Count Includes - Practice 2
A country count depends on the definition, reference date and treatment of territories or recognition.
Countries and territoriesgn6b1
Audit a country-count claim
Learn a common country count and the rule behind it.
Countries and territoriesgn810
Languages cross borders
Explore spoken and signed languages without confusing languages with countries.
World languagesgv310
Count carefully
Explore spoken and signed languages without confusing languages with countries.
World languagesgv510
Count Overlapping Language Groups - Practice 1
People may use more than one language, and languages can cross political borders.
World languagesgv7ba
Count Overlapping Language Groups - Practice 2
People may use more than one language, and languages can cross political borders.
World languagesgv7bb
Evaluate a language survey
Explore spoken and signed languages without confusing languages with countries.
World languagesgv810
Learn How Cuneiform Leaves Marks - Practice 1
Ancient Mesopotamian scribes used cuneiform, a writing system with wedge-shaped marks, often pressed into clay with a stylus.
Ancient civilizationsha3ck
Learn How Cuneiform Leaves Marks - Practice 2
Ancient Mesopotamian scribes used cuneiform, a writing system with wedge-shaped marks, often pressed into clay with a stylus.
Ancient civilizationsha3cl
Connect the Nile with Ancient Farming - Practice 1
The Nile supported ancient Egyptian agriculture through water, floodplain soils and transport.
Ancient civilizationsha4co
Connect the Nile with Ancient Farming - Practice 2
The Nile supported ancient Egyptian agriculture through water, floodplain soils and transport.
Ancient civilizationsha4cp
Mesopotamia: Writing and Record Keeping
Connect ancient writing with the practical needs of growing communities.
Ancient civilizationsha501
Ancient Egypt: Materials from the Nile
Connect environment, craft, and surviving evidence without treating geography as destiny.
Ancient civilizationsha601
Find Different Kinds of Records - Practice 1
Records of the past can include writing, pictures and objects.
Historical sourceshs1cc
Find Different Kinds of Records - Practice 2
Records of the past can include writing, pictures and objects.
Historical sourceshs1cd
Learn from Historical Objects
Use an object's features as evidence without guessing its whole story.
Historical sourceshs301
Compare Primary and Secondary Sources
Choose sources suited to a historical question.
Historical sourceshs401
Compare Two Accounts of One Event
Read what different sources agree on and what they leave uncertain.
Historical sourceshs402
Ask Which Record Can Answer the Question
Match historical claims to suitable evidence and notice gaps.
Historical sourceshs602
Ask Who Made a Historical Source - Practice 1
Identify creator, date, audience and purpose before using a record.
Historical sourceshs6cu
Ask Who Made a Historical Source - Practice 2
Identify creator, date, audience and purpose before using a record.
Historical sourceshs6cv
Check Whether Sources Are Independent - Practice 1
Two accounts repeating one original report are not two independent observations.
Historical sourceshs7cy
Check Whether Sources Are Independent - Practice 2
Two accounts repeating one original report are not two independent observations.
Historical sourceshs7cz
Separate Earlier Events from Proven Causes - Practice 1
An event happening first is necessary for some causal explanations, but order alone is not enough.
Historical sourceshs8d2
Separate Earlier Events from Proven Causes - Practice 2
An event happening first is necessary for some causal explanations, but order alone is not enough.
Historical sourceshs8d3
Read an Old Map with Its Own Date - Practice 1
A historical map shows choices made by its creator for a purpose and date.
Historical sourceshs8d4
Read an Old Map with Its Own Date - Practice 2
A historical map shows choices made by its creator for a purpose and date.
Historical sourceshs8d5
Notice What an Archive Does Not Cover - Practice 1
Surviving records are not a complete sample of everyone who lived.
Historical sourceshs9d6
Notice What an Archive Does Not Cover - Practice 2
Surviving records are not a complete sample of everyone who lived.
Historical sourceshs9d7
Reconcile Records with Different Units - Practice 1
Before calling two numerical records contradictory, compare dates, definitions and units.
Historical sourceshs9d8
Reconcile Records with Different Units - Practice 2
Before calling two numerical records contradictory, compare dates, definitions and units.
Historical sourceshs9d9
Use a Historical Quotation Carefully - Practice 1
A quotation needs provenance and context.
Historical sourceshsadc
Use a Historical Quotation Carefully - Practice 2
A quotation needs provenance and context.
Historical sourceshsadd
Distinguish a Surviving Sample from a Population - Practice 1
A proportion in surviving records describes that record set.
Historical sourceshsbde
Distinguish a Surviving Sample from a Population - Practice 2
A proportion in surviving records describes that record set.
Historical sourceshsbdf
Compare Changes without Overclaiming Causation - Practice 1
A difference-in-differences calculation subtracts the comparison group's change from the focal group's change.
Historical sourceshsbdg
Compare Changes without Overclaiming Causation - Practice 2
A difference-in-differences calculation subtracts the comparison group's change from the focal group's change.
Historical sourceshsbdh
Reconcile Historical Accounts and Missing Evidence
Build a qualified explanation from conflicting sources.
Historical sourceshsc01
Test Competing Historical Explanations - Practice 1
An explanation should state what evidence would distinguish it from alternatives.
Historical sourceshscdi
Test Competing Historical Explanations - Practice 2
An explanation should state what evidence would distinguish it from alternatives.
Historical sourceshscdj
Trace Provenance Before Counting Corroboration
Evaluate dependence among historical accounts.
Historical sourceshsd01
Archival Survival and Partial Identification
Bound a historical claim when record survival is selective.
Historical sourceshse01
Historical Corpus Search and OCR Measurement Error
Evaluate search accuracy before using hits as historical frequency evidence.
Historical sourceshse02
Look for Clues in Old Objects - Practice 1
Read with an adult.
Historical sourceshskc8
Look for Clues in Old Objects - Practice 2
Read with an adult.
Historical sourceshskc9
Look at a Picture from Before - Practice 1
Point, talk, and try with a trusted adult.
Historical sourceshsp0j
Look at a Picture from Before - Practice 2
Point, talk, and try with a trusted adult.
Historical sourceshsp0k
Compare Then and Now
Notice change and continuity in a place over time.
Timelinesht101
Read Events from a Labeled Timeline - Practice 1
A timeline puts events in order.
Timelinesht1ca
Read Events from a Labeled Timeline - Practice 2
A timeline puts events in order.
Timelinesht1cb
Put Events on a Timeline
Order dated events and find the time between them.
Timelinesht201
Measure Time between Two Year Marks - Practice 1
For these same-era year marks, subtract the earlier year from the later year.
Timelinesht2ce
Measure Time between Two Year Marks - Practice 2
For these same-era year marks, subtract the earlier year from the later year.
Timelinesht2cf
Read a Community Timeline
Put dated events in order and calculate elapsed years.
Timelinesht302
Order Records by Their Dates - Practice 1
For positive CE years, earlier years have smaller numbers.
Timelinesht3ci
Order Records by Their Dates - Practice 2
For positive CE years, earlier years have smaller numbers.
Timelinesht3cj
Count across BCE and CE without Year Zero - Practice 1
In the conventional BCE/CE year system there is no year zero: 1 BCE is followed by 1 CE.
Timelinesht4cm
Count across BCE and CE without Year Zero - Practice 2
In the conventional BCE/CE year system there is no year zero: 1 BCE is followed by 1 CE.
Timelinesht4cn
Measure Change Across a Longer Timeline
Compare intervals and avoid confusing elapsed years with counts of events.
Timelinesht502
Assign a Positive CE Year to Its Century - Practice 1
The first CE century runs from year 1 through 100.
Timelinesht5cq
Assign a Positive CE Year to Its Century - Practice 2
The first CE century runs from year 1 through 100.
Timelinesht5cr
Read BCE and CE Dates Carefully
Order dates across eras and account for the missing year zero.
Timelinesht801
Bound an Interval between Uncertain Dates - Practice 1
When an earlier event is dated within [a,b] and a later event within [c,d], the shortest possible gap is c-b and the longest is d-a when b<c.
Timelineshtcdk
Bound an Interval between Uncertain Dates - Practice 2
When an earlier event is dated within [a,b] and a later event within [c,d], the shortest possible gap is c-b and the longest is d-a when b<c.
Timelineshtcdl
Build Historical Date Bounds from Evidence
Use dated evidence to constrain an event without inventing an exact year.
Timelineshtd01
Past, Present, and Future
Use time words to begin thinking about history.
Timelineshtk01
Put a Short Event Sequence in Order - Practice 1
An adult can read each small story aloud.
Timelineshtkc6
Put a Short Event Sequence in Order - Practice 2
An adult can read each small story aloud.
Timelineshtkc7
First and Then in a Tiny Story - Practice 1
Point, talk, and try with a trusted adult.
Timelineshtp0h
First and Then in a Tiny Story - Practice 2
Point, talk, and try with a trusted adult.
Timelineshtp0i
Distinguish the Declaration and the Constitution
Compare the purposes and chronology of two United States founding documents.
United States historyhu901
Reconstruction: Constitutional Change and Enforcement
Distinguish constitutional protections from the struggle to enforce them.
United States historyhub01
Match Transport to Its Stated Power - Practice 1
Transport changed in many different ways across places and times.
World historyhw2cg
Match Transport to Its Stated Power - Practice 2
Transport changed in many different ways across places and times.
World historyhw2ch
Compare Hand Copying and Reusable Type - Practice 1
A manuscript is written by hand.
World historyhw5cs
Compare Hand Copying and Reusable Type - Practice 2
A manuscript is written by hand.
World historyhw5ct
Compare Production Records with Clear Units - Practice 1
Industrial history examines people, energy, tools and working conditions, not just bigger totals.
World historyhw6cw
Compare Production Records with Clear Units - Practice 2
Industrial history examines people, energy, tools and working conditions, not just bigger totals.
World historyhw6cx
The Silk Roads as Networks of Exchange
Understand trade routes as changing networks, not one road carrying one product.
World historyhw701
Balance a Historical Trade Ledger Model - Practice 1
Trade records may use local units and varied payment systems.
World historyhw7d0
Balance a Historical Trade Ledger Model - Practice 2
Trade records may use local units and varied payment systems.
World historyhw7d1
Industrialization: Production and Working Lives
Connect changing production systems with different experiences of industrial change.
World historyhwa01
Separate Nominal Prices from Constant-Price Values - Practice 1
A price index can adjust a nominal amount to base-period purchasing-power units: nominal amount x 100 / index when the base index is 100.
World historyhwada
Separate Nominal Prices from Constant-Price Values - Practice 2
A price index can adjust a nominal amount to base-period purchasing-power units: nominal amount x 100 / index when the base index is 100.
World historyhwadb
Compare Historical Mechanisms and Counterfactuals
Assess rival explanations using sequence, mechanisms, and comparison cases.
World historyhwe01
Make Ten to Add
Use ten as a stepping stone when adding within 20.
Additionma101
Count On to Add
Take small steps along a number line.
Additionma102
Find the Missing Part of Ten - Practice 1
Ten is the whole.
Additionma1aa
Find the Missing Part of Ten - Practice 2
Ten is the whole.
Additionma1ab
Add Tens and Ones
Add two-digit numbers by combining place values.
Additionma201
Add Across a Ten - Practice 1
Add the ones first.
Additionma2ak
Add Across a Ten - Practice 2
Add the ones first.
Additionma2al
Add Across Hundreds
Regroup ones and tens when adding three-digit numbers.
Additionma301
Join Two Small Groups - Practice 1
Count the objects in the first group, then keep counting through the second group.
Additionmaka4
Join Two Small Groups - Practice 2
Count the objects in the first group, then keep counting through the second group.
Additionmaka5
Plan a Pretend Craft Budget
Count money in, money out and what remains using whole cents.
Money and accountingmb390
Balance a Tiny Workshop's Books
Separate what a pretend workshop has, what it owes and the owner's remaining claim.
Money and accountingmb690
Use Derivatives to Find Instantaneous Rates
Apply the power rule and interpret the slope at a point.
Calculusmcc01
Differentiate a Power and Evaluate - Practice 1
For x^n with positive integer n, the derivative is n x^(n - 1).
Calculusmccdc
Differentiate a Power and Evaluate - Practice 2
For x^n with positive integer n, the derivative is n x^(n - 1).
Calculusmccdd
Build a Tangent Line at a Point - Practice 1
A tangent line uses the derivative as slope and passes through the point on the curve.
Calculusmccde
Build a Tangent Line at a Point - Practice 2
A tangent line uses the derivative as slope and passes through the point on the curve.
Calculusmccdf
Accumulate a Constant Rate - Practice 1
A constant rate over an interval accumulates rate times interval length.
Calculusmccdg
Accumulate a Constant Rate - Practice 2
A constant rate over an interval accumulates rate times interval length.
Calculusmccdh
Separate Average and Instantaneous Rate - Practice 1
Average rate over [a,b] is (f(b) - f(a)) / (b - a), for a not equal to b.
Calculusmccdi
Separate Average and Instantaneous Rate - Practice 2
Average rate over [a,b] is (f(b) - f(a)) / (b - a), for a not equal to b.
Calculusmccdj
Find a Stationary Point - Practice 1
For a differentiable function, a stationary point has derivative zero.
Calculusmccdk
Find a Stationary Point - Practice 2
For a differentiable function, a stationary point has derivative zero.
Calculusmccdl
Taylor Approximation with a Remainder Bound
Connect local polynomial approximations with a defensible error estimate.
Calculusmcd01
KKT Conditions and Constraint Sensitivity
Solve a constrained convex problem and interpret its multiplier.
Calculusmce01
Share Equally
Connect equal sharing, division, and multiplication.
Divisionmd301
Make Sense of Division Leftovers
Share objects equally and decide what the leftover means.
Divisionmd302
Share into Equal Groups - Practice 1
Division by a group count asks how many objects belong in each group.
Divisionmd3aw
Share into Equal Groups - Practice 2
Division by a group count asks how many objects belong in each group.
Divisionmd3ax
Divide with Friendly Chunks
Break a dividend into multiples you can divide easily.
Divisionmd401
Interpret a Remainder - Practice 1
Take as many full equal groups as possible.
Divisionmd4b6
Interpret a Remainder - Practice 2
Take as many full equal groups as possible.
Divisionmd4b7
Measure with Equal Tiles - Practice 1
Put equal-length tiles end to end, with no gaps and no overlaps.
Measurementme1ai
Measure with Equal Tiles - Practice 2
Put equal-length tiles end to end, with no gaps and no overlaps.
Measurementme1aj
Count Minutes Forward - Practice 1
For a short interval in one hour, subtract the starting minute from the ending minute.
Measurementme2aq
Count Minutes Forward - Practice 2
For a short interval in one hour, subtract the starting minute from the ending minute.
Measurementme2ar
Measure Elapsed Time
Find minutes that pass, including across an hour.
Measurementme301
Find a Missing Straight Angle - Practice 1
A straight angle measures 180 degrees.
Measurementme4ba
Find a Missing Straight Angle - Practice 2
A straight angle measures 180 degrees.
Measurementme4bb
Convert Meters to Centimeters - Practice 1
One meter equals 100 centimeters.
Measurementme5bk
Convert Meters to Centimeters - Practice 2
One meter equals 100 centimeters.
Measurementme5bl
Name Equal Parts
Recognize fractions as equal parts of one whole.
Fractionsmf301
Count Equal Fraction Parts - Practice 1
The denominator tells how many equal parts make the whole.
Fractionsmf3ay
Count Equal Fraction Parts - Practice 2
The denominator tells how many equal parts make the whole.
Fractionsmf3az
Build Equivalent Fractions
Make equivalent fractions by scaling both parts equally.
Fractionsmf401
Find Fractions of a Collection
Use equal groups to find a fraction of a whole-number amount.
Fractionsmf402
Scale Both Parts of a Fraction - Practice 1
Multiply numerator and denominator by the same nonzero number.
Fractionsmf4b8
Scale Both Parts of a Fraction - Practice 2
Multiply numerator and denominator by the same nonzero number.
Fractionsmf4b9
Add Fractions with Unlike Denominators
Rename fractions with common-sized parts before adding.
Fractionsmf501
Find a Fraction of a Set - Practice 1
Divide the whole count by the denominator to find one equal part.
Fractionsmf5be
Find a Fraction of a Set - Practice 2
Divide the whole count by the denominator to find one equal part.
Fractionsmf5bf
Walk Around a Rectangle - Practice 1
Perimeter is the distance around the outside.
Geometrymg2as
Walk Around a Rectangle - Practice 2
Perimeter is the distance around the outside.
Geometrymg2at
Cover a Rectangle with Unit Squares - Practice 1
Area counts the unit squares inside a shape.
Geometrymg3b0
Cover a Rectangle with Unit Squares - Practice 2
Area counts the unit squares inside a shape.
Geometrymg3b1
Separate Area from Perimeter
Distinguish covering a rectangle from measuring its boundary.
Geometrymg401
Build Volume One Layer at a Time
Count cubic units in rectangular prisms and use layers to find missing dimensions.
Geometrymg502
Build Volume from Layers - Practice 1
A rectangular prism has equal rectangular layers.
Geometrymg5bi
Build Volume from Layers - Practice 2
A rectangular prism has equal rectangular layers.
Geometrymg5bj
Use a Perpendicular Triangle Height - Practice 1
A triangle has half the area of a rectangle with the same base and perpendicular height.
Geometrymg6bw
Use a Perpendicular Triangle Height - Practice 2
A triangle has half the area of a rectangle with the same base and perpendicular height.
Geometrymg6bx
Find a Right-Triangle Hypotenuse - Practice 1
For a right triangle, the hypotenuse is opposite the right angle and satisfies c^2 = a^2 + b^2.
Geometrymg8ce
Find a Right-Triangle Hypotenuse - Practice 2
For a right triangle, the hypotenuse is opposite the right angle and satisfies c^2 = a^2 + b^2.
Geometrymg8cf
Use Right-Triangle Relationships
Choose between the Pythagorean theorem and trigonometric ratios.
Geometrymga01
Use Differences to Find Distance - Practice 1
The differences in x and y are perpendicular legs of a right triangle.
Geometrymgacs
Use Differences to Find Distance - Practice 2
The differences in x and y are perpendicular legs of a right triangle.
Geometrymgact
Average Corresponding Coordinates - Practice 1
The midpoint lies halfway between endpoints.
Geometrymgacu
Average Corresponding Coordinates - Practice 2
The midpoint lies halfway between endpoints.
Geometrymgacv
Divide a Polygon into Triangles - Practice 1
A simple convex n-sided polygon can be divided from one vertex into n - 2 triangles.
Geometrymgacw
Divide a Polygon into Triangles - Practice 2
A simple convex n-sided polygon can be divided from one vertex into n - 2 triangles.
Geometrymgacx
Square the Length Scale for Area - Practice 1
When every length is multiplied by k, two perpendicular dimensions both change.
Geometrymgacy
Square the Length Scale for Area - Practice 2
When every length is multiplied by k, two perpendicular dimensions both change.
Geometrymgacz
Read a Checkerboard
Count the playing squares and set up an English/American checkers game.
Checkersmh2c1
Choose a Legal Checkers Step
Trace an ordinary move and explain what diagonally forward means.
Checkersmh2c2
Checkers Jumps Come First
Look across the whole board before choosing a quiet move.
Checkersmh3c1
Follow a Complete Checkers Jump Trail
Keep the same piece moving until its capture turn is complete.
Checkersmh3c2
Checkers Kings: Crown and Stop
Separate the move that makes a king from what a king can do on a later turn.
Checkersmh4c1
Checkers: Think One Turn Ahead
Compare legal choices by checking the opponent's immediate reply.
Checkersmh4c2
Set Up a Chessboard
Count the squares and pieces, then check the starting arrangement.
Chessmj2c1
Read Chess Square Addresses
Use one letter and one number to name an exact square.
Chessmj2c2
Choose a Knight Move
Trace an L-shaped move and separate jumping from landing.
Chessmj3c1
Keep Your King Safe
Explain why a rook that shields its king cannot move sideways.
Chessmj3c2
Checkmate or Stalemate?
Compare two queen moves and ask whether the king is actually attacked.
Chessmj4c1
Chess: Look One Reply Ahead
Compare a tempting capture with a move that avoids an immediate rook loss.
Chessmj4c2
Evaluate Expressions Step by Step
Substitute a value for a variable and follow the order of operations.
Algebraml602
Measure Distance Across Zero - Practice 1
Distance is nonnegative.
Algebraml6bs
Measure Distance Across Zero - Practice 2
Distance is nonnegative.
Algebraml6bt
Substitute Before Calculating - Practice 1
Replace every occurrence of the variable with its value.
Algebraml6bu
Substitute Before Calculating - Practice 2
Replace every occurrence of the variable with its value.
Algebraml6bv
Solve Equations by Undoing Operations
Keep both sides equal while solving one- and two-step equations.
Algebraml701
Undo a Two-Step Equation - Practice 1
Undo addition or subtraction first, then multiplication or division.
Algebraml7by
Undo a Two-Step Equation - Practice 2
Undo addition or subtraction first, then multiplication or division.
Algebraml7bz
Multiply Signed Numbers - Practice 1
A product of two numbers with different signs is negative.
Algebraml7c6
Multiply Signed Numbers - Practice 2
A product of two numbers with different signs is negative.
Algebraml7c7
Find Slope and Starting Value
Connect a linear rule to changes in a table of values.
Algebraml801
Calculate Rise per Run - Practice 1
Slope is change in y divided by change in x.
Algebraml8c8
Calculate Rise per Run - Practice 2
Slope is change in y divided by change in x.
Algebraml8c9
Read a Linear Rule - Practice 1
A linear rule y = mx + b applies a constant rate m to the input and then adds b.
Algebraml8ca
Read a Linear Rule - Practice 2
A linear rule y = mx + b applies a constant rate m to the input and then adds b.
Algebraml8cb
Combine Powers with the Same Base - Practice 1
Multiplying powers of the same base joins their repeated factors, so add the exponents.
Algebraml8cc
Combine Powers with the Same Base - Practice 2
Multiplying powers of the same base joins their repeated factors, so add the exponents.
Algebraml8cd
Use Sum and Difference Together - Practice 1
Add the two equations to remove one variable when its coefficients are opposites.
Algebraml8cg
Use Sum and Difference Together - Practice 2
Add the two equations to remove one variable when its coefficients are opposites.
Algebraml8ch
Solve Quadratics by Factoring
Use factors and the zero-product rule to find both solutions.
Algebraml901
Evaluate a Quadratic Carefully - Practice 1
Square the input before multiplying by a coefficient.
Algebraml9ci
Evaluate a Quadratic Carefully - Practice 2
Square the input before multiplying by a coefficient.
Algebraml9cj
Use the Zero-Product Rule - Practice 1
If two factors multiply to zero, at least one factor equals zero.
Algebraml9ck
Use the Zero-Product Rule - Practice 2
If two factors multiply to zero, at least one factor equals zero.
Algebraml9cl
Find a Term by Its Position - Practice 1
An arithmetic sequence adds the same difference at each step.
Algebraml9cm
Find a Term by Its Position - Practice 2
An arithmetic sequence adds the same difference at each step.
Algebraml9cn
Model Exponential Growth and Decay
Distinguish a constant multiplier from a constant addition.
Algebramlb01
Apply the Inner Function First - Practice 1
In f(g(x)), apply g to x first, then use that result as the input of f.
Algebramlbd2
Apply the Inner Function First - Practice 2
In f(g(x)), apply g to x first, then use that result as the input of f.
Algebramlbd3
Reverse a Linear Function - Practice 1
To reverse y = ax + b with nonzero a, subtract b and divide by a.
Algebramlbd4
Reverse a Linear Function - Practice 2
To reverse y = ax + b with nonzero a, subtract b and divide by a.
Algebramlbd5
Count Repeated Multiplications - Practice 1
A geometric sequence multiplies by the same ratio each step.
Algebramlbd6
Count Repeated Multiplications - Practice 2
A geometric sequence multiplies by the same ratio each step.
Algebramlbd7
Read a Logarithm as an Exponent - Practice 1
For positive base b not equal to 1, log base b of a positive number asks which exponent on b produces that number.
Algebramlbd8
Read a Logarithm as an Exponent - Practice 2
For positive base b not equal to 1, log base b of a positive number asks which exponent on b produces that number.
Algebramlbd9
Least Squares as an Orthogonal Projection
Derive a fitted constant and connect residuals to the normal equations.
Algebramld01
Identifiability and Ridge Regularization
Analyze what observations identify before interpreting a stabilized estimate.
Algebramle01
Count Equal Pairs - Practice 1
A pair contains two.
Multiplicationmm1ag
Count Equal Pairs - Practice 2
A pair contains two.
Multiplicationmm1ah
Equal Groups to Multiplication
Turn equal groups into repeated addition and multiplication.
Multiplicationmm301
Read Rows and Columns - Practice 1
An array has the same number in every row.
Multiplicationmm3au
Read Rows and Columns - Practice 2
An array has the same number in every row.
Multiplicationmm3av
Multiply by Breaking Apart
Multiply a two-digit number using tens and ones.
Multiplicationmm401
Break Apart a Multiplication - Practice 1
Split one factor into convenient parts.
Multiplicationmm4b4
Break Apart a Multiplication - Practice 2
Split one factor into convenient parts.
Multiplicationmm4b5
Count in Twos, Fives, and Tens
Use equal jumps to continue counting patterns.
Countingmn101
Count and Find the Next Number
Count small sets and follow the numbers from 1 to 10.
Countingmnk01
Count, Compare, and Find One More
Compare small groups and change a count by one.
Countingmnk02
Count Each Dot Once - Practice 1
Point to one dot and say one number.
Countingmnka0
Count Each Dot Once - Practice 2
Point to one dot and say one number.
Countingmnka1
Take One More Step - Practice 1
Say the starting number.
Countingmnka2
Take One More Step - Practice 2
Say the starting number.
Countingmnka3
Find the Larger Group - Practice 1
Count each group separately.
Countingmnka8
Find the Larger Group - Practice 2
Count each group separately.
Countingmnka9
Point and Count to Five - Practice 1
Point, talk, and try with a trusted adult.
Countingmnp01
Point and Count to Five - Practice 2
Point, talk, and try with a trusted adult.
Countingmnp02
Find the Number That Breaks the Rule
Be a number detective: state the rule, test each item and explain the exception.
Patterns and reasoningmo391
Sort Numbers with Two Rules
Test both conditions before putting a number in the accepted group.
Patterns and reasoningmo492
An Unusual Value Is a Clue
Use a stated review rule without treating a flag as proof of a mistake.
Patterns and reasoningmo591
Compare AND with OR
Use a stated logical connector to decide which readings qualify.
Patterns and reasoningmo692
Finish a Shape Pattern - Practice 1
Point, talk, and try with a trusted adult.
Patterns and reasoningmop03
Finish a Shape Pattern - Practice 2
Point, talk, and try with a trusted adult.
Patterns and reasoningmop04
Build Tens and Ones
Make numbers with groups of ten and single blocks.
Place valuemp101
Build a Number from Tens and Ones - Practice 1
A ten is a group of ten ones.
Place valuemp1ae
Build a Number from Tens and Ones - Practice 2
A ten is a group of ten ones.
Place valuemp1af
Build Three-Digit Numbers
Read hundreds, tens, and ones and explain their values.
Place valuemp201
Read Hundreds, Tens and Ones - Practice 1
Each hundreds block represents 100, each tens rod 10 and each single one 1.
Place valuemp2ao
Read Hundreds, Tens and Ones - Practice 2
Each hundreds block represents 100, each tens rod 10 and each single one 1.
Place valuemp2ap
Round by Finding the Midpoint
Use the halfway point to round whole numbers.
Place valuemp301
Round to the Nearest Hundred - Practice 1
Find the two neighboring hundreds.
Place valuemp4bc
Round to the Nearest Hundred - Practice 2
Find the two neighboring hundreds.
Place valuemp4bd
Connect Decimals and Hundredths - Practice 1
A hundredth is one of 100 equal parts of one whole.
Place valuemp5bg
Connect Decimals and Hundredths - Practice 2
A hundredth is one of 100 equal parts of one whole.
Place valuemp5bh
Solitaire: Two Card Paths
Explain why a card belongs on a foundation or in a column.
Solitairemq3s1
Solitaire: Deal and Draw One
Count the cards, then find which stock or waste card is available.
Solitairemq3s2
Solitaire: Uncover a New Choice
Compare two legal moves by what changes immediately afterward.
Solitairemq4s1
Solitaire: Notice a Repeated Pass
Follow the waste order and distinguish a legal action from a useful new choice.
Solitairemq4s2
Build Equivalent Ratios and Unit Rates
Scale both parts of a ratio and find an amount for one unit.
Ratiosmr601
Compare Using a Unit Rate - Practice 1
Divide the total by the number of equal units.
Ratiosmr6bo
Compare Using a Unit Rate - Practice 2
Divide the total by the number of equal units.
Ratiosmr6bp
Find Ten Percent - Practice 1
Percent means per hundred.
Ratiosmr6bq
Find Ten Percent - Practice 2
Percent means per hundred.
Ratiosmr6br
Find the New Amount after an Increase - Practice 1
Find the increase as a part of the original amount, then add it to the original.
Ratiosmr7c0
Find the New Amount after an Increase - Practice 2
Find the increase as a part of the original amount, then add it to the original.
Ratiosmr7c1
Use a Fixed Map Scale - Practice 1
A scale links a map length to a real distance.
Ratiosmr7c2
Use a Fixed Map Scale - Practice 2
A scale links a map length to a real distance.
Ratiosmr7c3
Scale Corresponding Lengths - Practice 1
In similar figures, corresponding lengths have the same scale factor.
Ratiosmr9cq
Scale Corresponding Lengths - Practice 2
In similar figures, corresponding lengths have the same scale factor.
Ratiosmr9cr
Use Opposite over Hypotenuse - Practice 1
For an acute angle in a right triangle, sine is opposite-side length divided by hypotenuse length.
Ratiosmrad0
Use Opposite over Hypotenuse - Practice 2
For an acute angle in a right triangle, sine is opposite-side length divided by hypotenuse length.
Ratiosmrad1
Subtract by Counting Up
Use related addition facts to find a missing amount.
Subtractionms101
Take Away with Dots
Cross out dots and count what is left.
Subtractionms102
Subtract from Teen Numbers - Practice 1
Keep the ones while removing one group of ten.
Subtractionms1ac
Subtract from Teen Numbers - Practice 2
Keep the ones while removing one group of ten.
Subtractionms1ad
Subtract with a Regrouped Ten
Exchange one ten for ten ones before subtracting.
Subtractionms201
Exchange a Ten to Subtract - Practice 1
When there are too few ones to subtract, exchange one ten for ten ones.
Subtractionms2am
Exchange a Ten to Subtract - Practice 2
When there are too few ones to subtract, exchange one ten for ten ones.
Subtractionms2an
Subtract Across a Zero
Regroup hundreds and tens to subtract through a zero.
Subtractionms301
Take Away and Count What Remains - Practice 1
Start with the whole group.
Subtractionmska6
Take Away and Count What Remains - Practice 2
Start with the whole group.
Subtractionmska7
Combine Counts in a Table - Practice 1
Read the row label before the number.
Statisticsmt3b2
Combine Counts in a Table - Practice 2
Read the row label before the number.
Statisticsmt3b3
Find Mean, Median, and Range
Use different summaries to describe the same small data set.
Statisticsmt501
Find the Mean of Four Counts - Practice 1
Add all the values, then divide by how many values there are.
Statisticsmt5bm
Find the Mean of Four Counts - Practice 2
Add all the values, then divide by how many values there are.
Statisticsmt5bn
Choose Samples That Match a Question
Distinguish a target population from a convenient sample.
Statisticsmt701
Scale a Stated Sample Proportion - Practice 1
Use the observed fraction to make an estimate for a larger same-sized-unit population.
Statisticsmt7c4
Scale a Stated Sample Proportion - Practice 2
Use the observed fraction to make an estimate for a larger same-sized-unit population.
Statisticsmt7c5
Use Conditional Probabilities
Change the denominator when the condition changes.
Statisticsmt901
Sort Before Finding a Median - Practice 1
Order the values from least to greatest.
Statisticsmt9co
Sort Before Finding a Median - Practice 2
Order the values from least to greatest.
Statisticsmt9cp
Compare Overall and Grouped Rates
See how group composition can reverse an apparent comparison.
Statisticsmtb01
Keep the Weights in an Average - Practice 1
Multiply each value by its frequency.
Statisticsmtbda
Keep the Weights in an Average - Practice 2
Multiply each value by its frequency.
Statisticsmtbdb
Bayesian Updating and Model-Conditional Uncertainty
Derive a conjugate posterior and examine what its uncertainty leaves out.
Statisticsmte01
Math Facts
Connect addition, subtraction, multiplication, and division facts.
Mixed factsmx301
Find the Same Letter - Practice 1
Point, talk, and try with a trusted adult.
Letters and soundsrap05
Find the Same Letter - Practice 2
Point, talk, and try with a trusted adult.
Letters and soundsrap06
Compare Two Solutions
Compare the same features in two short texts.
Compare and contrastrc401
Compare Two Options Using Stated Features - Practice 1
Organize the same features for both options before comparing.
Compare and contrastrc4d4
Compare Two Options Using Stated Features - Practice 2
Organize the same features for both options before comparing.
Compare and contrastrc4d5
Compare Two Plans Using Evidence
Compare approaches to the same goal without inventing details.
Compare and contrastrc501
Compare Perspectives on a Shared Event
Explain how two accounts emphasize different aspects of the same experience.
Compare and contrastrc801
Synthesize Sources Without Erasing Limits
Combine complementary findings while preserving each source's scope.
Compare and contrastrcb01
Combine Sources without Erasing Their Differences - Practice 1
Compare sources by scope, timing and method before treating them as contradictory.
Compare and contrastrcbdi
Combine Sources without Erasing Their Differences - Practice 2
Compare sources by scope, timing and method before treating them as contradictory.
Compare and contrastrcbdj
Read a Research Claim Against Its Design
Separate an estimate, its uncertainty, and the claim a design can support.
Compare and contrastrcd01
Synthesize Estimates Without Hiding Heterogeneity
Evaluate a pooled estimate and the assumptions behind its weights.
Compare and contrastrce01
Compare Effects Rather Than Significance Labels
Evaluate a moderation claim using the actual contrast and its uncertainty.
Compare and contrastrce02
Find Details in the Kite Story
Look back at a short story to find who, what, and where.
Detailsrd101
Reading Details
Find details in a passage about a class garden.
Detailsrd201
Read Instructions and Their Conditions
Track requirements, exceptions, and deadlines in a notice.
Detailsrd501
Operational Definitions and the Claims They Permit
Distinguish an observed indicator from the broader concept it is meant to measure.
Detailsrdd01
Listen for Story Details
Listen to a short story and notice who, what, and where.
Detailsrdk01
Listen for Small Story Details - Practice 1
An adult can read the story and choices aloud.
Detailsrdkcw
Listen for Small Story Details - Practice 2
An adult can read the story and choices aloud.
Detailsrdkcx
Listen and Find the Picture - Practice 1
Point, talk, and try with a trusted adult.
Detailsrdp07
Listen and Find the Picture - Practice 2
Point, talk, and try with a trusted adult.
Detailsrdp08
Check a Headline Against the Details
Distinguish what a headline claims from what its evidence supports.
Media literacyre401
Check What a Survey Really Says
Compare an advertisement with the group and question behind its numbers.
Media literacyre602
Evaluate Sponsored Claims
Separate persuasive intent from evidence for a product claim.
Media literacyre701
Report a Count without Changing Its Scope - Practice 1
State the group that was actually counted.
Media literacyre7bq
Report a Count without Changing Its Scope - Practice 2
State the group that was actually counted.
Media literacyre7br
Trace a Claim to Its Evidence
Distinguish repeated claims from independent observations.
Media literacyre7d1
Check Dates, Context and Corrections
Use a source for the question it can actually answer.
Media literacyre7d2
Separate a Proposal from Its Supporting Evidence - Practice 1
A proposal recommends an action.
Media literacyre7da
Separate a Proposal from Its Supporting Evidence - Practice 2
A proposal recommends an action.
Media literacyre7db
Keep an Idea Connected to Its Source - Practice 1
When summarizing a source, identify whose information or idea it is.
Media literacyre8bw
Keep an Idea Connected to Its Source - Practice 2
When summarizing a source, identify whose information or idea it is.
Media literacyre8bx
Match a Claim to the Evidence Provided - Practice 1
A claim should stay within the information actually given.
Media literacyre8by
Match a Claim to the Evidence Provided - Practice 2
A claim should stay within the information actually given.
Media literacyre8bz
Read a Comparison without Inventing a Cause - Practice 1
When two groups differ, ask how the groups were formed and what else differed.
Media literacyre8dc
Read a Comparison without Inventing a Cause - Practice 2
When two groups differ, ask how the groups were formed and what else differed.
Media literacyre8dd
Limit a Conclusion to the Observed Sample - Practice 1
Use qualifiers to distinguish a finding in a sample from a universal claim.
Media literacyre9c2
Limit a Conclusion to the Observed Sample - Practice 2
Use qualifiers to distinguish a finding in a sample from a universal claim.
Media literacyre9c3
Identify How a Writer Supports a Position - Practice 1
Look at the writer's goal and how details are selected to advance it.
Media literacyre9de
Identify How a Writer Supports a Position - Practice 2
Look at the writer's goal and how details are selected to advance it.
Media literacyre9df
Turn a Vague Outcome into a Defined Measure - Practice 1
An operational definition states what will be recorded and under what procedure.
Media literacyreace
Turn a Vague Outcome into a Defined Measure - Practice 2
An operational definition states what will be recorded and under what procedure.
Media literacyreacf
Check Whether the Method Supports the Conclusion - Practice 1
Read a study description for who was included, what was measured and how comparison conditions were assigned.
Media literacyreadg
Check Whether the Method Supports the Conclusion - Practice 2
Read a study description for who was included, what was measured and how comparison conditions were assigned.
Media literacyreadh
Read Percentage Claims with Their Baselines
Distinguish relative change, percentage points, and unsupported explanations.
Media literacyreb01
Preserve Some without Turning It into All - Practice 1
Quantifiers determine the scope of a claim.
Media literacyrebcg
Preserve Some without Turning It into All - Practice 2
Quantifiers determine the scope of a claim.
Media literacyrebch
Retain the Denominator in a Percentage Report - Practice 1
A percentage describes a fraction of a defined group.
Media literacyrebci
Retain the Denominator in a Percentage Report - Practice 2
A percentage describes a fraction of a defined group.
Media literacyrebcj
Keep a One-Way Rule Pointing the Right Way - Practice 1
A statement if P then Q does not by itself establish if Q then P.
Media literacyrebck
Keep a One-Way Rule Pointing the Right Way - Practice 2
A statement if P then Q does not by itself establish if Q then P.
Media literacyrebcl
Paraphrase without Increasing Certainty - Practice 1
A faithful paraphrase changes wording while preserving attribution, scope and uncertainty.
Media literacyrecco
Paraphrase without Increasing Certainty - Practice 2
A faithful paraphrase changes wording while preserving attribution, scope and uncertainty.
Media literacyreccp
Separate an Association from a Causal Claim - Practice 1
A comparison of self-selected groups can reveal an association without isolating a cause.
Media literacyreccq
Separate an Association from a Causal Claim - Practice 2
A comparison of self-selected groups can reveal an association without isolating a cause.
Media literacyreccr
State What a Measure Does Not Establish - Practice 1
A narrowly defined measure can be useful without covering an entire construct.
Media literacyreccs
State What a Measure Does Not Establish - Practice 2
A narrowly defined measure can be useful without covering an entire construct.
Media literacyrecct
Audit a Summary for Scope, Uncertainty and Missing Data - Practice 1
A research summary should preserve the design, observed result and important limitations.
Media literacyrecdk
Audit a Summary for Scope, Uncertainty and Missing Data - Practice 2
A research summary should preserve the design, observed result and important limitations.
Media literacyrecdl
Audit Missing Evidence in a Research Synthesis
Construct a sensitivity analysis for selective reporting.
Media literacyree01
Find a Word That Names a Thing - Practice 1
A noun can name a person, place or thing.
Grammarrg1a8
Find a Word That Names a Thing - Practice 2
A noun can name a person, place or thing.
Grammarrg1a9
Find the Action Word - Practice 1
A verb can tell what someone or something does.
Grammarrg1aa
Find the Action Word - Practice 2
A verb can tell what someone or something does.
Grammarrg1ab
Make a Regular Plural - Practice 1
A singular noun names one.
Grammarrg2ag
Make a Regular Plural - Practice 2
A singular noun names one.
Grammarrg2ah
Learn Plurals That Change Form - Practice 1
Some plural nouns change more than their endings.
Grammarrg2ai
Learn Plurals That Change Form - Practice 2
Some plural nouns change more than their endings.
Grammarrg2aj
Match One or More with Is and Are - Practice 1
Use is with one thing and are with more than one in these present-tense sentences.
Grammarrg2ak
Match One or More with Is and Are - Practice 2
Use is with one thing and are with more than one in these present-tense sentences.
Grammarrg2al
Tell What Happened Yesterday - Practice 1
A past-tense verb can describe a completed action.
Grammarrg2am
Tell What Happened Yesterday - Practice 2
A past-tense verb can describe a completed action.
Grammarrg2an
Connect Ideas by Their Relationship - Practice 1
Because introduces a reason; but introduces a contrast; and can add a compatible idea.
Grammarrg4b2
Connect Ideas by Their Relationship - Practice 2
Because introduces a reason; but introduces a contrast; and can add a compatible idea.
Grammarrg4b3
Find the Subject beyond an Intervening Phrase - Practice 1
A phrase between the subject and verb does not change which noun controls agreement.
Grammarrg5b4
Find the Subject beyond an Intervening Phrase - Practice 2
A phrase between the subject and verb does not change which noun controls agreement.
Grammarrg5b5
Replace a Pronoun When Two People Fit - Practice 1
A pronoun should point clearly to its intended referent.
Grammarrg5b6
Replace a Pronoun When Two People Fit - Practice 2
A pronoun should point clearly to its intended referent.
Grammarrg5b7
Give a Dependent Clause a Main Clause - Practice 1
A clause beginning with although can leave an unfinished relationship.
Grammarrg6be
Give a Dependent Clause a Main Clause - Practice 2
A clause beginning with although can leave an unfinished relationship.
Grammarrg6bf
Name Who Performs the Opening Action - Practice 1
An introductory participial phrase should describe the subject that immediately follows.
Grammarrg6bg
Name Who Performs the Opening Action - Practice 2
An introductory participial phrase should describe the subject that immediately follows.
Grammarrg6bh
Keep Listed Actions Parallel - Practice 1
Items serving the same role in a list should follow a matching grammatical pattern.
Grammarrg7bk
Keep Listed Actions Parallel - Practice 2
Items serving the same role in a list should follow a matching grammatical pattern.
Grammarrg7bl
Choose a Subject Pronoun in a Pair - Practice 1
When a pronoun is part of a compound subject, use its subject form.
Grammarrg7bm
Choose a Subject Pronoun in a Pair - Practice 2
When a pronoun is part of a compound subject, use its subject form.
Grammarrg7bn
Name the Agent in an Active Revision - Practice 1
An active clause makes the doer its subject.
Grammarrg8bs
Name the Agent in an Active Revision - Practice 2
An active clause makes the doer its subject.
Grammarrg8bt
Signal the Intended Logical Relationship - Practice 1
Choose a transition by the relationship between propositions, not by how impressive it sounds.
Grammarrg9c4
Signal the Intended Logical Relationship - Practice 2
Choose a transition by the relationship between propositions, not by how impressive it sounds.
Grammarrg9c5
Use Were in an Unreal Formal Condition - Practice 1
For the unreal conditions specified here, formal edited English uses were with I, he, she or a singular noun.
Grammarrgaca
Use Were in an Unreal Formal Condition - Practice 2
For the unreal conditions specified here, formal edited English uses were with I, he, she or a singular noun.
Grammarrgacb
Preserve Parallel Infinitive Phrases - Practice 1
When a list states purposes using to plus a base verb, keep the coordinated purposes in that same form.
Grammarrgacc
Preserve Parallel Infinitive Phrases - Practice 2
When a list states purposes using to plus a base verb, keep the coordinated purposes in that same form.
Grammarrgacd
Use an Action as a Clue - Practice 1
A story may explain a reason directly or give a clue through an action.
Inferenceri2d0
Use an Action as a Clue - Practice 2
A story may explain a reason directly or give a clue through an action.
Inferenceri2d1
Use Clues to Infer
Combine details to make an inference the text supports.
Inferenceri301
Infer a Character's Changing Feelings
Use actions and speech as evidence for an inference.
Inferenceri401
Infer Without Jumping to Conclusions
Use story clues to distinguish a reasonable inference from a guess.
Inferenceri402
Support an Inference without Pretending to Know - Practice 1
Connect several clues to an interpretation, then check whether another explanation remains possible.
Inferenceri5d6
Support an Inference without Pretending to Know - Practice 2
Connect several clues to an interpretation, then check whether another explanation remains possible.
Inferenceri5d7
Distinguish Evidence from Assumption
Judge how strongly observations support a claim.
Inferenceri601
Distinguish a Narrator's View from Everyone's View - Practice 1
Identify what the narrator directly observes and what is an interpretation.
Inferenceri6d8
Distinguish a Narrator's View from Everyone's View - Practice 2
Identify what the narrator directly observes and what is an interpretation.
Inferenceri6d9
Separate a Narrator's Belief from Evidence
Evaluate a first-person explanation using details the narrator may overlook.
Inferenceri701
Read Irony Through Context
Distinguish literal wording from a context-supported ironic meaning.
Inferenceria01
Capital Letters: Sentence Starts and I
Practice capital letters at the start of a sentence and in the word I.
Capitalizationrk101
Begin a Sentence with a Capital - Practice 1
Capitalize the first letter of a written sentence.
Capitalizationrk1ac
Begin a Sentence with a Capital - Practice 2
Capitalize the first letter of a written sentence.
Capitalizationrk1ad
Capital Letters in Names, Days, and Months
Find the difference between a specific name and an ordinary word.
Capitalizationrk201
Capitalization in Book and Story Titles
Practice a stated title style without treating every word alike.
Capitalizationrk401
Capitalization: Names, Roles, and General Words
Edit capitalization using what each word means in its sentence.
Capitalizationrk601
Match Lowercase and Uppercase Letters - Practice 1
A letter can have a lowercase and an uppercase form.
Capitalizationrkka6
Match Lowercase and Uppercase Letters - Practice 2
A letter can have a lowercase and an uppercase form.
Capitalizationrkka7
Find the Main Idea
Separate a passage's main idea from its supporting details.
Main idearm301
Separate the Main Idea from a Detail - Practice 1
Ask what most of the passage explains.
Main idearm3d2
Separate the Main Idea from a Detail - Practice 2
Ask what most of the passage explains.
Main idearm3d3
Connect Details to a Main Idea
Find the idea supported by an entire informational passage.
Main idearm401
Summarize a Repair Project
Choose a summary that connects a problem, actions and results.
Main idearm502
Trace Claims, Reasons, and Counterarguments
Analyze the structure of an argument without confusing a concession with its conclusion.
Main idearm901
Punctuation: Periods, Questions, and Exclamations
Choose the ending that fits a statement, a question, or a strong feeling.
Punctuationrp101
Choose a Statement or Question Ending - Practice 1
A direct question asks something and usually ends with a question mark.
Punctuationrp1ae
Choose a Statement or Question Ending - Practice 2
A direct question asks something and usually ends with a question mark.
Punctuationrp1af
Commas in Lists and Direct Address
Use commas to separate list items and a person being spoken to.
Punctuationrp201
Apostrophes: Shortened Words and Ownership
Distinguish missing letters, ownership, and ordinary plurals.
Punctuationrp301
Show Missing Letters in a Contraction - Practice 1
A contraction combines words and marks omitted letters with an apostrophe.
Punctuationrp3ao
Show Missing Letters in a Contraction - Practice 2
A contraction combines words and marks omitted letters with an apostrophe.
Punctuationrp3ap
Show One Person Owns Something - Practice 1
For the singular names used here, add apostrophe s to show ownership.
Punctuationrp3aq
Show One Person Owns Something - Practice 2
For the singular names used here, add apostrophe s to show ownership.
Punctuationrp3ar
Punctuation in Spoken Dialogue
Place quotation marks around exact speech and punctuate speech tags.
Punctuationrp401
Show Ownership by a Regular Plural - Practice 1
For a plural noun already ending in s, add only an apostrophe after that s to show ownership.
Punctuationrp4aw
Show Ownership by a Regular Plural - Practice 2
For a plural noun already ending in s, add only an apostrophe after that s to show ownership.
Punctuationrp4ax
Place Punctuation in Direct Speech - Practice 1
These exercises use American English dialogue conventions.
Punctuationrp4ay
Place Punctuation in Direct Speech - Practice 2
These exercises use American English dialogue conventions.
Punctuationrp4az
Commas Between Clauses and Around Extra Details
Use sentence structure to decide where a comma belongs.
Punctuationrp501
Separate Three Items Consistently - Practice 1
For these exercises, use a serial comma before and in a list of three items.
Punctuationrp5b8
Separate Three Items Consistently - Practice 2
For these exercises, use a serial comma before and in a list of three items.
Punctuationrp5b9
Semicolons and Colons: Connect and Introduce
Choose punctuation by checking whether the first part is a complete clause.
Punctuationrp601
Join Complete Clauses without a Comma Splice - Practice 1
A comma alone does not normally join two independent clauses in formal prose.
Punctuationrp6bc
Join Complete Clauses without a Comma Splice - Practice 2
A comma alone does not normally join two independent clauses in formal prose.
Punctuationrp6bd
Close an Inserted Parenthesis - Practice 1
Parentheses enclose an aside.
Punctuationrp7bo
Close an Inserted Parenthesis - Practice 2
Parentheses enclose an aside.
Punctuationrp7bp
Introduce a List after a Complete Clause - Practice 1
A colon can introduce a list after a complete introductory clause.
Punctuationrp8bu
Introduce a List after a Complete Clause - Practice 2
A colon can introduce a list after a complete introductory clause.
Punctuationrp8bv
Keep an Identifying Clause Attached - Practice 1
A restrictive clause identifies which members of a group are meant.
Punctuationrp9c0
Keep an Identifying Clause Attached - Practice 2
A restrictive clause identifies which members of a group are meant.
Punctuationrp9c1
Punctuate However between Complete Clauses - Practice 1
When however connects two complete clauses within one sentence, use a semicolon before it and a comma after it in this formal pattern.
Punctuationrpac8
Punctuate However between Complete Clauses - Practice 2
When however connects two complete clauses within one sentence, use a semicolon before it and a comma after it in this formal pattern.
Punctuationrpac9
Introduce a Quoted Sentence after a Speech Tag - Practice 1
For the American English convention used here, a short speech tag such as wrote takes a comma before a complete quotation.
Punctuationrpbcm
Introduce a Quoted Sentence after a Speech Tag - Practice 2
For the American English convention used here, a short speech tag such as wrote takes a comma before a complete quotation.
Punctuationrpbcn
Follow the Seed Steps
Put a short set of planting steps in order.
Sequencers101
Follow a Short Sequence - Practice 1
Look for the order in which actions happen.
Sequencers1cy
Follow a Short Sequence - Practice 2
Look for the order in which actions happen.
Sequencers1cz
Put Events in Order
Follow time words to rebuild a short sequence.
Sequencers201
Put the Puppet Show in Order
Follow steps and explain why their order matters.
Sequencers302
Solve Words from Context
Use nearby explanations and contrasts to understand words.
Vocabularyrv301
Read the Prefix Un - Practice 1
The prefix un often means not when added to these adjectives.
Vocabularyrv3as
Read the Prefix Un - Practice 2
The prefix un often means not when added to these adjectives.
Vocabularyrv3at
Use a Sentence to Find a Similar Meaning - Practice 1
A synonym has a similar meaning in a particular context.
Vocabularyrv3au
Use a Sentence to Find a Similar Meaning - Practice 2
A synonym has a similar meaning in a particular context.
Vocabularyrv3av
Use Contrast and Examples as Word Clues
Infer word meanings from nearby contrasts and examples.
Vocabularyrv401
Choose the Word That Fits Its Meaning - Practice 1
Some words sound alike but have different spellings and meanings.
Vocabularyrv4b0
Choose the Word That Fits Its Meaning - Practice 2
Some words sound alike but have different spellings and meanings.
Vocabularyrv4b1
Read Common Prefix Meanings - Practice 1
A prefix can change a base word in a predictable way, but context still matters.
Vocabularyrv5ba
Read Common Prefix Meanings - Practice 2
A prefix can change a base word in a predictable way, but context still matters.
Vocabularyrv5bb
Match a Word to a Formal Notice - Practice 1
Choose language suited to the stated audience.
Vocabularyrv6bi
Match a Word to a Formal Notice - Practice 2
Choose language suited to the stated audience.
Vocabularyrv6bj
Replace a Vague Reference with the Named Item - Practice 1
A precise revision can repeat a noun rather than leave this or it with several possible references.
Vocabularyrv9c6
Replace a Vague Reference with the Named Item - Practice 2
A precise revision can repeat a noun rather than leave this or it with several possible references.
Vocabularyrv9c7
Analyze Diction and Unstated Assumptions
Examine how wording frames a proposal before evidence is considered.
Vocabularyrvc01
Shorten a Sentence without Losing Its Limits - Practice 1
Concise editing removes unnecessary wording while retaining the claim, population and qualification.
Vocabularyrvccu
Shorten a Sentence without Losing Its Limits - Practice 2
Concise editing removes unnecessary wording while retaining the claim, population and qualification.
Vocabularyrvccv
Notice the First Letter - Practice 1
An adult may read the words aloud.
Vocabularyrvka0
Notice the First Letter - Practice 2
An adult may read the words aloud.
Vocabularyrvka1
Notice the Last Letter - Practice 1
An adult may read the words aloud.
Vocabularyrvka2
Notice the Last Letter - Practice 2
An adult may read the words aloud.
Vocabularyrvka3
Hear a Rhyming Pair - Practice 1
Ask an adult to say each choice.
Vocabularyrvka4
Hear a Rhyming Pair - Practice 2
Ask an adult to say each choice.
Vocabularyrvka5
Explain Day and Night
Connect daylight with Earth's rotation.
Astronomysa201
Put the Planets in Order
Build a solar-system lineup, starting nearest the Sun.
Astronomysa391
Why the Moon Has Phases
Distinguish changing views of the Moon's lit half from eclipses.
Astronomysa401
Compare Planet Families
Classify planets and notice what a simplified picture cannot tell you.
Astronomysa591
Connect Earth's Tilt with Seasons
Explain seasonal changes in daylight and Sun angle.
Astronomysa601
Gravity and Orbital Motion
Combine forward motion with inward gravitational acceleration.
Astronomysa901
Propagate Correlated Astronomical Measurement Errors
Derive uncertainty in luminosity and distinguish it from model error.
Astronomysae01
Warm-Blooded and Cold-Blooded Animals
Discover how warm-blooded and cold-blooded animals get the heat their bodies need.
Animal body temperaturesb201
Sort Warm-Blooded and Cold-Blooded Animals
Use animal groups to compare warm-blooded and cold-blooded examples.
Animal body temperaturesb301
How Animals Warm Up and Cool Down
Compare temperature-control behaviors in warm-blooded and cold-blooded animals.
Animal body temperaturesb401
Compare Animal Body Temperature Data
Use a simplified data set to explore warm-blooded and cold-blooded temperature patterns.
Animal body temperaturesb501
Programming Basics: Read a Tiny Program
Trace a drawing program without skipping instructions.
Programming basicssc170
Programming Basics: Find and Fix a Bug
Compare what you wanted with what your instructions actually did.
Programming basicssc270
Programming Basics: Track a Variable
Keep a record of a value as instructions change it.
Programming basicssc370
Programming Basics: Choose One Branch
Use a true-or-false condition to choose an action.
Programming basicssc470
Programming Basics: Repeat a Group of Steps
Trace a fixed-count loop and notice which instructions are inside it.
Programming basicssc570
Programming Basics: Make a While Loop Stop
Check a condition before each repetition and track progress toward stopping.
Programming basicssc670
Programming Basics: Call a Function
Separate a function definition from a call and trace its returned value.
Programming basicssc770
Programming Basics: Read and Update a List
Use a stated position convention and distinguish values from positions.
Programming basicssc870
Programming Basics: Combine Boolean Conditions
Build truth tables rather than guessing how AND, OR and NOT behave.
Programming basicssc970
Programming Basics: Test the Edges
Turn a requirement into test cases before editing a program.
Programming basicssca70
Programming Basics: Separate Calculation and Display
Split responsibilities into small functions with clear contracts.
Programming basicsscb70
Programming Basics: Count the Work
Compare operation counts under a clearly stated cost model.
Programming basicsscc70
Programming Basics: Prove a Loop Invariant
Prove that a counting loop sums the integers from 1 through n.
Programming basicsscd70
Programming Basics: Derive a Weakest Precondition
Reason backward through assignments rather than relying only on examples.
Programming basicssce70
Programming Basics: Put Steps in Order
Follow a short list of drawing instructions.
Programming basicssck70
Ship a Change Carefully
Help a pretend learning site change safely, one small step at a time.
DevOpssd690
Read a Release Gate
Use test evidence, recovery limits and secret-handling rules to evaluate a release.
DevOpssd990
Electronics Basics: Open or Closed?
Trace a complete path through a simple circuit.
Electronics basicsse180
Electronics Basics: Conductors and Insulators
Match conducting cores and insulating coverings to their jobs.
Electronics basicsse280
Electronics Basics: Match Components to Jobs
Recognize what common electronic components do.
Electronics basicsse380
Electronics Basics: Voltage Is Not Current
Keep volts, amps and energy transfer separate.
Electronics basicsse480
Electronics Basics: Follow a Series Path
Trace one path and use the same current through series parts.
Electronics basicsse580
Electronics Basics: Follow Parallel Branches
Distinguish shared voltage from divided current.
Electronics basicsse680
Electronics Basics: Use Ohm's Law Carefully
Calculate with V = I R and state the model's limits.
Electronics basicsse780
Electronics Basics: Read an LED Circuit Model
Use polarity and a stated forward-voltage approximation.
Electronics basicsse880
Count Charge Transferred by a Constant Current - Practice 1
Current is charge transferred per unit time.
Electronics basicsse8ce
Count Charge Transferred by a Constant Current - Practice 2
Current is charge transferred per unit time.
Electronics basicsse8cf
Electronics Basics: Power and Energy
Distinguish the rate of energy transfer from total energy.
Electronics basicsse980
Electronics Basics: Notice Divider Loading
Check whether a connected load changes the voltage divider.
Electronics basicssea80
Electronics Basics: Read Logic Levels
Use ideal logic values without confusing them with universal voltages.
Electronics basicsseb80
Electronics Basics: Trace Capacitor Charging
Read the time constant of an ideal resistor-capacitor model.
Electronics basicssec80
Electronics Basics: Use a Thevenin Equivalent
Replace a linear source network by its port behavior.
Electronics basicssed80
Electronics Basics: Analyze an RC Low-Pass Filter
Connect an ideal circuit model to transient and frequency behavior.
Electronics basicssee80
Electronics Basics: Meet the Circuit Parts
Find the source, wires, switch and lamp in a picture.
Electronics basicssek80
Gravity: Follow the Pull
Find the direction of gravity in everyday observations.
Forcessf120
Falling Speeds: Read the Gaps
Use equal-time pictures to notice a change in speed.
Forcessf140
Hydraulic Press: Follow a Push
Trace how a push can be passed through trapped liquid.
Forcessf160
Gravity and Things That Hold Us Up
Explain why an object can stay still while gravity acts.
Forcessf220
Falling Speeds: Fair Starts Without Air
Separate falling speed from a guess based only on mass.
Forcessf240
Hydraulic Press: Compare Piston Faces
Count equal squares to compare the areas of two faces.
Forcessf260
Notice Pushes and Pulls
Connect forces with changes in motion.
Forcessf301
Gravity and Falling Paper
Discover why the same paper can fall differently after changing shape.
Forcessf320
Wind and Air: Name the Wind
Distinguish the source direction of wind from the direction it travels.
Forcessf330
Falling Speeds: Measure Average Speed
Turn distance and elapsed time into an average, with units.
Forcessf340
Hydraulic Press: Share Pressure, Change Force
Separate a shared pressure from different piston forces.
Forcessf360
Compare Balanced and Unbalanced Forces
Use force size and direction to predict changes in motion.
Forcessf401
Gravity: Plan a Fair Drop Test
Use repeated trials to compare two shapes of the same paper.
Forcessf420
Wind and Air: Read Speeds and Gusts
Read a fictional wind record and preserve units, time and location.
Forcessf430
Falling Speeds: Repeat the Measurement
Read repeated fall times and notice measurement limits.
Forcessf440
Hydraulic Press: Trade Force for Distance
See why a stronger output push travels a shorter distance.
Forcessf460
Gravity Without Air Resistance
Separate a no-air model from falling objects in everyday air.
Forcessf520
Wind and Air: Follow a Sea Breeze
Trace a simplified daytime circulation between water and warmer land.
Forcessf530
Falling Speeds: Shape and a Fair Test
Plan an observation that changes shape without confusing other factors.
Forcessf540
Hydraulic Press: Audit the Work
Check the energy budget instead of calling a machine magic.
Forcessf560
Gravity: Calculate Mass and Weight
Use kilograms for mass and newtons for gravitational force.
Forcessf620
Wind and Air: Pressure Makes a Push
Use pressure differences and area to calculate a net force.
Forcessf630
Falling Speeds: A Speed Increase Each Second
Use a constant-acceleration model without mixing up speed and acceleration.
Forcessf640
Hydraulic Press: Calculate Pressure
Use SI units to connect force, area and pressure.
Forcessf660
Gravity: Compare Worlds and Scales
Distinguish gravitational weight, mass, and a scale reading.
Forcessf720
Wind and Air: Heating and Weather Models
Explain pressure-driven motion without turning a useful model into an absolute rule.
Forcessf730
Falling Speeds: Average Versus Final Speed
Use distance totals to distinguish an interval average from a momentary speed.
Forcessf740
Hydraulic Press: Square the Diameter Ratio
Distinguish diameter ratios from area ratios.
Forcessf760
Connect Net Force, Mass, and Acceleration
Apply Newton's second law in simple one-dimensional models.
Forcessf801
Gravity: Why Satellites Stay in Orbit
Use direction arrows to explain circular motion and apparent weightlessness.
Forcessf820
Wind and Air: Relative Motion and Drag
Compare air forces while stating which quantities stay fixed.
Forcessf830
Falling Speeds: Terminal Does Not Mean Stopped
Read weight and drag arrows before describing the motion.
Forcessf840
Hydraulic Press: Trace Flow and Power
Connect volume per second with piston speed and power.
Forcessf860
Gravity and the Inverse-Square Rule
Reason with proportional changes in mass and center-to-center distance.
Forcessf920
Wind and Air: Compressible Gas Models
Use absolute pressure and temperature in ideal-gas comparisons.
Forcessf930
Falling Speeds: Estimate a Terminal Speed
Use a force balance and state what is held constant.
Forcessf940
Hydraulic Press: Track Efficiency and Losses
Distinguish energy loss from the ideal force ratio.
Forcessf960
Gravity: Model Vertical Free Fall
Use constant-acceleration equations with a clear sign convention.
Forcessfa20
Wind and Air: Flow Through a Narrowing
Combine continuity with a carefully limited Bernoulli model.
Forcessfa30
Falling Speeds: Height, Time and Landing Speed
Connect three variables in a clearly bounded free-fall calculation.
Forcessfa40
Hydraulic Press: Include Height Differences
Apply hydrostatic pressure changes without misusing Pascal's principle.
Forcessfa60
Gravity and Changes in Energy
Distinguish near-surface energy changes from the full inverse-distance model.
Forcessfb20
Wind and Air: Available Wind Power
Calculate energy flow without promising turbine output.
Forcessfb30
Falling Speeds: Account for Energy in a Fall
Compare an ideal energy conversion with a fall that includes drag.
Forcessfb40
Hydraulic Press: Account for the Piston Rod
Calculate the effective annular area on the rod side.
Forcessfb60
Gravity: Circular Orbits and Escape Energy
Compare circular speed, orbital energy and escape speed in an ideal model.
Forcessfc20
Wind and Air: Scale an Airflow Experiment
Use Reynolds number to judge whether a small model represents a larger flow.
Forcessfc30
Falling Speeds: Measure Speed with Uncertainty
Estimate timing resolution and propagate small independent uncertainties.
Forcessfc40
Hydraulic Press: Keep an Energy Ledger
Include changing stored energy before reporting efficiency.
Forcessfc60
Gravity Inside and Outside a Uniform Sphere
Derive a continuous spherical field and potential using the shell theorem.
Forcessfd20
Wind and Air: Derive an Atmospheric Profile
Combine hydrostatic balance and an ideal-gas model with explicit assumptions.
Forcessfd30
Falling Speeds: Solve the Linear-Drag Model
Derive a time-dependent fall from a first-order differential equation.
Forcessfd40
Hydraulic Press: Model Fluid Compliance
Derive a small-signal pressure transient for a fixed-volume chamber.
Forcessfd60
Gravity: Tidal Fields and Local Free Fall
Analyze relative acceleration without confusing a local free-fall frame with the absence of curvature.
Forcessfe20
Wind and Air: Geostrophic Balance and Limits
Derive a pressure-driven wind with consistent signs and a scale analysis.
Forcessfe30
Falling Speeds: Analyze Quadratic-Drag Relaxation
Nondimensionalize a nonlinear fall and test its limiting behavior.
Forcessfe40
Hydraulic Press: Analyze Coupled Dynamics
Use a linear hydraulic actuator model to connect stiffness, damping and stability.
Forcessfe60
Gravity: What Falls Down?
An adult can read the questions aloud. Watch a soft ball move toward the floor.
Forcessfk20
Falling Speeds: Watch a Fall
Put pictures of a falling ball in order, with an adult reading along.
Forcessfk40
Hydraulic Press: Spot the Parts
Find the liquid, the connecting tube and the two moving piston faces.
Forcessfk60
Look Closely at Rocks
Describe a rock's visible features before naming it.
Geologysg101
Rocks and Minerals Are Not the Same
Distinguish a mineral's properties from a rock made of materials.
Geologysg301
Three rock families
Follow the clues that show how rocks form and change.
Geologysg310
Follow More Than One Rock-Cycle Path
Connect rock types with the processes that form them.
Geologysg401
Separate Breaking Down from Moving Away - Practice 1
Weathering breaks material down in place.
Geologysg4b6
Separate Breaking Down from Moving Away - Practice 2
Weathering breaks material down in place.
Geologysg4b7
Separate Weathering, Erosion, and Deposition
Track whether material is breaking down, moving, or settling.
Geologysg501
Weathering and erosion
Follow the clues that show how rocks form and change.
Geologysg510
Read Fossils as Evidence of Past Life
Distinguish body fossils, traces, and the limits of preservation.
Geologysg601
Connect Plate Motion with Boundary Processes
Compare divergent, convergent, and transform boundaries.
Geologysg701
Order Rock Layers and Cutting Events
Use superposition and cross-cutting relationships to reconstruct a sequence.
Geologysg801
Read the rock record
Follow the clues that show how rocks form and change.
Geologysg810
Model Half-Life in Rock Dating
Use repeated halving while recognizing dating assumptions.
Geologysga01
Combine Relative Ages with Dating Uncertainty
Bracket a layer's age while keeping assumptions and uncertainty visible.
Geologysgc01
Scale a Geological Diffusion Model
Nondimensionalize diffusion before comparing processes at different lengths.
Geologysgd01
Nonunique Geological Mixtures and Independent Tracers
Use a simplified inverse problem to distinguish precision from identifiability.
Geologysge01
Match Habitats to Needs
Use evidence about food, water, shelter, and space.
Habitatssh201
Choose a Habitat from Stated Needs - Practice 1
Read the needs in this fictional habitat puzzle.
Habitatssh2aq
Choose a Habitat from Stated Needs - Practice 2
Read the needs in this fictional habitat puzzle.
Habitatssh2ar
Connect Adaptations to Habitats
Match a described feature to the job it helps an organism do.
Habitatssh301
Follow Energy Through a Food Web
Read food-web arrows and reason about connected populations.
Habitatssh501
Reason with a Logistic Population Model
Explore how limited resources affect a simplified population-growth model.
Habitatsshb01
Meet the Computer Team
Follow a drawing from your fingers to the screen and into a saved file.
Computer partssi390
Follow Input, Processing and Output
Follow information through a computer without confusing its parts.
Computer partssi493
Keep Working Memory and Saved Files Separate
Explain RAM, storage and unsaved changes.
Computer partssi593
Memory Is Not Storage
Use a fictional device report to tell working memory from saved-file space.
Computer partssi690
When a Pattern Guesses Wrong
Explore how examples can suggest a pattern without proving it always works.
AI literacysj590
Test a Predictor on Unseen Examples
Calculate a result, inspect mistakes and explain what a small test cannot prove.
AI literacysj890
Use Proton Count to Identify Atomic Number - Practice 1
Atomic number is the number of protons in an atom's nucleus.
Chemistrysk7by
Use Proton Count to Identify Atomic Number - Practice 2
Atomic number is the number of protons in an atom's nucleus.
Chemistrysk7bz
Read Whether a Formula Contains One Element or More - Practice 1
An element contains one kind of atom, even when its atoms occur in molecules.
Chemistrysk7c0
Read Whether a Formula Contains One Element or More - Practice 2
An element contains one kind of atom, even when its atoms occur in molecules.
Chemistrysk7c1
Multiply a Subscript by the Number of Molecules - Practice 1
A subscript states how many atoms of an element are in one molecule.
Chemistrysk7c2
Multiply a Subscript by the Number of Molecules - Practice 2
A subscript states how many atoms of an element are in one molecule.
Chemistrysk7c3
Separate Mass Number from Atomic Number - Practice 1
Mass number is the number of protons plus neutrons in a particular nucleus.
Chemistrysk8c8
Separate Mass Number from Atomic Number - Practice 2
Mass number is the number of protons plus neutrons in a particular nucleus.
Chemistrysk8c9
Check Atom Conservation in a Balanced Model - Practice 1
A balanced chemical equation preserves the count of each element.
Chemistrysk8cg
Check Atom Conservation in a Balanced Model - Practice 2
A balanced chemical equation preserves the count of each element.
Chemistrysk8ch
Use Total Solution Mass as the Denominator - Practice 1
Mass percent is solute mass divided by total solution mass, multiplied by 100.
Chemistrysk9ci
Use Total Solution Mass as the Denominator - Practice 2
Mass percent is solute mass divided by total solution mass, multiplied by 100.
Chemistrysk9cj
Conserve Solute during an Ideal Dilution - Practice 1
For a compatible ideal dilution with no reaction or solute loss, concentration times solution volume stays constant.
Chemistrysk9ck
Conserve Solute during an Ideal Dilution - Practice 2
For a compatible ideal dilution with no reaction or solute loss, concentration times solution volume stays constant.
Chemistrysk9cl
Apply an Inverse Pressure-Volume Model - Practice 1
For a fixed amount of ideal gas at constant absolute temperature, pressure times volume is constant.
Chemistryskacs
Apply an Inverse Pressure-Volume Model - Practice 2
For a fixed amount of ideal gas at constant absolute temperature, pressure times volume is constant.
Chemistryskact
Convert Sample Mass into Moles - Practice 1
Amount in moles equals sample mass divided by molar mass.
Chemistryskacu
Convert Sample Mass into Moles - Practice 2
Amount in moles equals sample mass divided by molar mass.
Chemistryskacv
Use a Balanced Equation as a Mole Ratio - Practice 1
Coefficients in a balanced reaction give relative amounts in moles.
Chemistryskacw
Use a Balanced Equation as a Mole Ratio - Practice 2
Coefficients in a balanced reaction give relative amounts in moles.
Chemistryskacx
Follow Repeated Half-Life Intervals - Practice 1
In an ideal exponential-decay model, the expected undecayed amount halves each half-life.
Chemistryskacy
Follow Repeated Half-Life Intervals - Practice 2
In an ideal exponential-decay model, the expected undecayed amount halves each half-life.
Chemistryskacz
Use Solution Volume in Molarity - Practice 1
Molarity is moles of solute per liter of solution.
Chemistryskbd2
Use Solution Volume in Molarity - Practice 2
Molarity is moles of solute per liter of solution.
Chemistryskbd3
Track a One-to-One Equivalence Calculation - Practice 1
For the specified complete one-to-one reaction, equivalence means equal reacting amounts in moles.
Chemistryskbd4
Track a One-to-One Equivalence Calculation - Practice 2
For the specified complete one-to-one reaction, equivalence means equal reacting amounts in moles.
Chemistryskbd5
Compare a Reaction Quotient with Its Equilibrium Constant - Practice 1
For the stated ideal reaction A <-> B at fixed temperature, use Q = [B]/[A] with consistent standard-state conventions.
Chemistryskcde
Compare a Reaction Quotient with Its Equilibrium Constant - Practice 2
For the stated ideal reaction A <-> B at fixed temperature, use Q = [B]/[A] with consistent standard-state conventions.
Chemistryskcdf
Think about What Green Plants Need - Practice 1
Green plants use light, water and carbon dioxide to make sugars.
Life sciencesl1aa
Think about What Green Plants Need - Practice 2
Green plants use light, water and carbon dioxide to make sugars.
Life sciencesl1ab
Follow a Stated Life-Cycle Sequence - Practice 1
Read the supplied sequence before answering.
Life sciencesl1ai
Follow a Stated Life-Cycle Sequence - Practice 2
Read the supplied sequence before answering.
Life sciencesl1aj
Match Plant Parts with Their Jobs
Connect the parts of a flowering plant with basic functions.
Life sciencesl201
Use a Seed-Dispersal Structure as a Clue - Practice 1
A structure can help a seed move away from its parent plant.
Life sciencesl2am
Use a Seed-Dispersal Structure as a Clue - Practice 2
A structure can help a seed move away from its parent plant.
Life sciencesl2an
Measure a Seedling's Height Change - Practice 1
Compare the same plant at two stated times, using the same units.
Life sciencesl2ao
Measure a Seedling's Height Change - Practice 2
Compare the same plant at two stated times, using the same units.
Life sciencesl2ap
A Green Plant Makes Its Food
Follow the jobs of roots, stems and leaves in a simplified green plant.
Life sciencesl391
Follow Energy through a Food Chain - Practice 1
In these food chains, arrows point from food to the organism that consumes it.
Life sciencesl3aw
Follow Energy through a Food Chain - Practice 2
In these food chains, arrows point from food to the organism that consumes it.
Life sciencesl3ax
Read a Population Count without Guessing Why - Practice 1
Compare counts taken with the stated same method.
Life sciencesl4bc
Read a Population Count without Guessing Why - Practice 2
Compare counts taken with the stated same method.
Life sciencesl4bd
Photosynthesis and Plant Needs
Distinguish making sugars from taking up water and minerals.
Life sciencesl501
Follow Energy through a Food Web
Read feeding arrows and follow more than one path through a model.
Life sciencesl591
Distinguish a Producer from a Consumer - Practice 1
A producer makes organic food from inorganic inputs using an energy source.
Life sciencesl5bk
Distinguish a Producer from a Consumer - Practice 2
A producer makes organic food from inorganic inputs using an energy source.
Life sciencesl5bl
Calculate the Fraction of Seeds That Sprouted - Practice 1
Count sprouted seeds over all seeds in the stated trial, including those that did not sprout.
Life sciencesl5bm
Calculate the Fraction of Seeds That Sprouted - Practice 2
Count sprouted seeds over all seeds in the stated trial, including those that did not sprout.
Life sciencesl5bn
Match a Cell Structure to Its Main Stated Role - Practice 1
Cells contain structures with different roles.
Life sciencesl6bo
Match a Cell Structure to Its Main Stated Role - Practice 2
Cells contain structures with different roles.
Life sciencesl6bp
Compare Photosynthesis and Cellular Respiration - Practice 1
Photosynthesis stores energy in organic molecules using light in the cases here.
Life sciencesl7c6
Compare Photosynthesis and Cellular Respiration - Practice 2
Photosynthesis stores energy in organic molecules using light in the cases here.
Life sciencesl7c7
Compare Plant and Animal Cells
Connect cell structures with their functions without treating all cells as identical.
Life sciencesl801
Include Births, Deaths and Movement - Practice 1
Population bookkeeping over a stated interval adds births and immigration and subtracts deaths and emigration.
Life sciencesl9co
Include Births, Deaths and Movement - Practice 2
Population bookkeeping over a stated interval adds births and immigration and subtracts deaths and emigration.
Life sciencesl9cp
Use Magnification with Matching Length Units - Practice 1
Magnification is image length divided by actual length when both use the same units.
Life sciencesl9cq
Use Magnification with Matching Length Units - Practice 2
Magnification is image length divided by actual length when both use the same units.
Life sciencesl9cr
Use an Inheritance Model Without Overclaiming
Connect allele combinations with probabilities in a simplified dominant-recessive model.
Life scienceslb01
Read a Simplified Single-Gene Cross - Practice 1
These fictional traits follow one autosomal locus with two alleles, equal gamete probabilities, and complete dominance of A.
Life scienceslbd8
Read a Simplified Single-Gene Cross - Practice 2
These fictional traits follow one autosomal locus with two alleles, equal gamete probabilities, and complete dominance of A.
Life scienceslbd9
Compare Energy Transfer between Defined Levels - Practice 1
Transfer efficiency is energy entering the next defined trophic level divided by energy available at the source level, times 100.
Life scienceslbda
Compare Energy Transfer between Defined Levels - Practice 2
Transfer efficiency is energy entering the next defined trophic level divided by energy available at the source level, times 100.
Life scienceslbdb
Distinguish Species Richness from Evenness - Practice 1
Species richness counts distinct species present.
Life scienceslcdi
Distinguish Species Richness from Evenness - Practice 2
Species richness counts distinct species present.
Life scienceslcdj
Enzyme Saturation and Michaelis-Menten Parameters
Interpret a saturation curve without turning its parameters into unsupported biological claims.
Life sciencesld01
Hierarchical Replication and Variance of a Mean
Derive how shared environments change the information in biological observations.
Life sciencesle01
Meet the Parts of a Flowering Plant - Practice 1
An adult can read these clues aloud.
Life scienceslka4
Meet the Parts of a Flowering Plant - Practice 2
An adult can read these clues aloud.
Life scienceslka5
A Message Across the Room
Discover how a local network can connect devices without a trip across the internet.
Networkingsn490
Put a Packet Message Back in Order
Use numbered paper pieces to model ordering and missing information.
Networkingsn593
Find a Route in a Paper Network
Trace connections and explain the limits of hop counts.
Networkingsn693
Names, Addresses and Network Delays
Separate finding an address from reaching a service, and delay from capacity.
Networkingsn790
Observe Before You Guess
Separate things you can notice from guesses about them.
Observationso101
Science Observations
Use observations from a plant investigation.
Observationso301
Notice Colors, Shapes, and Sounds
Practice careful observation using familiar, safe examples.
Observationsok01
Notice What a Picture Actually Shows - Practice 1
An adult can read the choices aloud.
Observationsoka0
Notice What a Picture Actually Shows - Practice 2
An adult can read the choices aloud.
Observationsoka1
Name the Weather Being Observed - Practice 1
Read each outdoor description with an adult.
Observationsoka6
Name the Weather Being Observed - Practice 2
Read each outdoor description with an adult.
Observationsoka7
Choose a Safe Observation Tool - Practice 1
An adult can read these paper situations aloud.
Observationsoka8
Choose a Safe Observation Tool - Practice 2
An adult can read these paper situations aloud.
Observationsoka9
Notice a Shape - Practice 1
Point, talk, and try with a trusted adult.
Observationsop09
Notice a Shape - Practice 2
Point, talk, and try with a trusted adult.
Observationsop0a
Wind and Air: An Invisible Filling
Use observations to show that air takes up space and can move.
Properties of mattersp130
Compare Solids, Liquids and Gases - Practice 1
Use familiar samples under the stated conditions.
Properties of mattersp1ac
Compare Solids, Liquids and Gases - Practice 2
Use familiar samples under the stated conditions.
Properties of mattersp1ad
Sort Solids, Liquids, and Gases
Use shape and space to describe common states of matter.
Properties of mattersp201
Wind and Air: A Mixture Around Us
Read a model of dry air without treating air as pure oxygen.
Properties of mattersp230
Investigate Mixtures and Dissolving
Use descriptions to distinguish dissolving from visible mixing.
Properties of mattersp301
Use a Magnet Test without Overgeneralizing - Practice 1
Some materials are strongly attracted to an ordinary magnet and others are not.
Properties of mattersp3au
Use a Magnet Test without Overgeneralizing - Practice 2
Some materials are strongly attracted to an ordinary magnet and others are not.
Properties of mattersp3av
Keep Track of Mass in a Closed Container - Practice 1
For these paper models, nothing enters or leaves a sealed container and the container stays on the balance.
Properties of mattersp3ay
Keep Track of Mass in a Closed Container - Practice 2
For these paper models, nothing enters or leaves a sealed container and the container stays on the balance.
Properties of mattersp3az
Choose a Separation Method from Properties - Practice 1
Choose from the stated properties of a mixture.
Properties of mattersp3b2
Choose a Separation Method from Properties - Practice 2
Choose from the stated properties of a mixture.
Properties of mattersp3b3
Follow Melting, Freezing and Condensing
Track water's state before and after a change.
Properties of mattersp402
Add Masses without Inventing a Volume Rule - Practice 1
In a closed paper model with no material loss, combined mass is the sum of component masses.
Properties of mattersp5be
Add Masses without Inventing a Volume Rule - Practice 2
In a closed paper model with no material loss, combined mass is the sum of component masses.
Properties of mattersp5bf
Track Solute after Water Leaves - Practice 1
A dissolved substance has not simply vanished.
Properties of mattersp5bg
Track Solute after Water Leaves - Practice 2
A dissolved substance has not simply vanished.
Properties of mattersp5bh
Compare Mass, Volume and Density
Use a defined ratio to compare how much mass occupies a volume.
Properties of mattersp602
Calculate Density from Mass and Volume - Practice 1
Density is mass divided by volume for the sample and conditions.
Properties of mattersp6bq
Calculate Density from Mass and Volume - Practice 2
Density is mass divided by volume for the sample and conditions.
Properties of mattersp6br
Use Average Density in an Ideal Floating Model - Practice 1
For a freely moving object in a uniform liquid, ignoring surface tension and attachments, an average density below the liquid allows floating.
Properties of mattersp8cc
Use Average Density in an Ideal Floating Model - Practice 2
For a freely moving object in a uniform liquid, ignoring surface tension and attachments, an average density below the liquid allows floating.
Properties of mattersp8cd
Conserve Atoms When Balancing Equations
Count atoms on both sides without changing a substance's formula.
Properties of mattersp901
Use Mole Ratios from Balanced Equations
Convert between reactant and product amounts in a theoretical reaction.
Properties of matterspa01
Wind and Air: Notice a Breeze
An adult can read the questions aloud. Notice what moving air can do.
Properties of matterspk30
Describe a Material by Its Properties - Practice 1
Read the supplied observation with an adult.
Properties of matterspka2
Describe a Material by Its Properties - Practice 2
Read the supplied observation with an adult.
Properties of matterspka3
Select Just the Text You Need
Predict what changes when typing replaces selected text.
Digital skillssq3d1
Copy or Cut in a Text Editor
Keep a source with Copy, or remove selected source text with Cut.
Digital skillssq3d2
Follow a File Trail
Use a folder path to find the right file, even when names repeat.
Digital skillssq4d1
Copy, Move or Rename a File
Predict what changes and what stays the same after a file action.
Digital skillssq4d2
Follow Undo and Redo
Trace a short editing history without confusing undo with saving.
Digital skillssq4d3
Check Focus, Then Use a Shortcut
Connect common edit commands to the active text box and the intended selection.
Digital skillssq4d4
Choose Who Can See Shared Work
Separate the audience from what each person is allowed to do.
Digital skillssq5d1
Understand What Stopping a Share Does
Distinguish future access from copies that already exist.
Digital skillssq5d2
Pause and Check an Unexpected Message
Choose a safe next step without opening links or sharing a login code.
Digital skillssq6d1
Keep Account Protections Separate
Understand unique passwords, extra sign-in checks and recovery without writing real secrets.
Digital skillssq6d2
Separate Light Sources from Reflectors - Practice 1
A light source emits visible light of its own in the stated situation.
Light and wavessr1ae
Separate Light Sources from Reflectors - Practice 2
A light source emits visible light of its own in the stated situation.
Light and wavessr1af
Locate a Shadow beyond an Opaque Object - Practice 1
In a simple straight-line light model, an opaque object blocks some light.
Light and wavessr1ag
Locate a Shadow beyond an Opaque Object - Practice 2
In a simple straight-line light model, an opaque object blocks some light.
Light and wavessr1ah
Measure Reflection Angles from the Normal - Practice 1
The normal is a line perpendicular to the surface at the point where a ray meets it.
Light and wavessr5bi
Measure Reflection Angles from the Normal - Practice 2
The normal is a line perpendicular to the surface at the point where a ray meets it.
Light and wavessr5bj
Count Frequency rather than Loudness - Practice 1
Frequency is the number of complete cycles per second.
Light and wavessr6bw
Count Frequency rather than Loudness - Practice 2
Frequency is the number of complete cycles per second.
Light and wavessr6bx
Connect Wavelength, Frequency and Wave Speed - Practice 1
For a periodic wave, speed equals frequency times wavelength.
Light and wavessr8ca
Connect Wavelength, Frequency and Wave Speed - Practice 2
For a periodic wave, speed equals frequency times wavelength.
Light and wavessr8cb
Find the Time for One Cycle - Practice 1
For a periodic signal, period is the reciprocal of frequency.
Light and wavessrad0
Find the Time for One Cycle - Practice 2
For a periodic signal, period is the reciprocal of frequency.
Light and wavessrad1
Relate Photon Energy to Frequency - Practice 1
For an individual photon, E = h f.
Light and wavessrcdc
Relate Photon Energy to Frequency - Practice 2
For an individual photon, E = h f.
Light and wavessrcdd
Compare an Absorbency Record - Practice 1
Use the same starting amount of water and the same test time to compare samples.
Investigationsst2as
Compare an Absorbency Record - Practice 2
Use the same starting amount of water and the same test time to compare samples.
Investigationsst2at
Read a Seedling Observation Log
Read measurements, find changes and keep guesses separate from observations.
Investigationsst302
Describe Variation across Repeated Readings - Practice 1
Repeated measurements may differ.
Investigationsst3b0
Describe Variation across Repeated Readings - Practice 2
Repeated measurements may differ.
Investigationsst3b1
Plan a Fair Investigation
Separate the changed condition, measurements, and controls.
Investigationsst401
Identify a Comparison with One Deliberate Change - Practice 1
To investigate one factor, deliberately vary it while keeping relevant conditions alike and measuring the same outcome.
Investigationsst4b8
Identify a Comparison with One Deliberate Change - Practice 2
To investigate one factor, deliberately vary it while keeping relevant conditions alike and measuring the same outcome.
Investigationsst4b9
Compare Repeated Trials
Use repeated measurements to compare designs carefully.
Investigationsst501
Separate Predictions from Results
Use a test record to compare an idea with evidence.
Investigationsst502
Match Conclusions to Measurement Limits
Use ranges, overlap, and measurement precision responsibly.
Investigationsst601
Scale a Sample Density Carefully - Practice 1
Estimate abundance by dividing counted organisms by sampled area, then multiplying by total comparable area.
Investigationsst6bu
Scale a Sample Density Carefully - Practice 2
Estimate abundance by dividing counted organisms by sampled area, then multiplying by total comparable area.
Investigationsst6bv
Design a Controlled Comparison
Separate a changed variable, a measured outcome, and controlled conditions.
Investigationsst701
Interpret Confidence Intervals in an Experiment
Separate an estimated effect, uncertainty, and the limits of a study design.
Investigationsstc01
Propagate Stated Worst-Case Bounds in a Sum - Practice 1
For quantities added, stated absolute error bounds add in a worst-case bound when every combination within the bounds is allowed.
Investigationsstcdk
Propagate Stated Worst-Case Bounds in a Sum - Practice 2
For quantities added, stated absolute error bounds add in a worst-case bound when every combination within the bounds is allowed.
Investigationsstcdl
Compare Thermal Insulation under a Fixed Test - Practice 1
Insulation reduces the rate of heat transfer; it does not create warmth.
Thermal energysu4b4
Compare Thermal Insulation under a Fixed Test - Practice 2
Insulation reduces the rate of heat transfer; it does not create warmth.
Thermal energysu4b5
Keep the Sign of a Temperature Change - Practice 1
Temperature change is final temperature minus initial temperature.
Thermal energysu6bs
Keep the Sign of a Temperature Change - Practice 2
Temperature change is final temperature minus initial temperature.
Thermal energysu6bt
Identify the Described Heat-Transfer Mechanism - Practice 1
Conduction transfers energy through interactions in material without bulk flow.
Thermal energysu7c4
Identify the Described Heat-Transfer Mechanism - Practice 2
Conduction transfers energy through interactions in material without bulk flow.
Thermal energysu7c5
Calculate Energy for a Temperature Rise - Practice 1
Within a single phase and a range where specific heat is treated as constant, transferred heat is mass times specific heat times temperature change.
Thermal energysu9cm
Calculate Energy for a Temperature Rise - Practice 2
Within a single phase and a range where specific heat is treated as constant, transferred heat is mass times specific heat times temperature change.
Thermal energysu9cn
Rearrange the Heat Model to Find Specific Heat - Practice 1
Under a constant-specific-heat, single-phase model with no unaccounted energy transfer, c = Q/(m deltaT).
Thermal energysubd6
Rearrange the Heat Model to Find Specific Heat - Practice 2
Under a constant-specific-heat, single-phase model with no unaccounted energy transfer, c = Q/(m deltaT).
Thermal energysubd7
Connect Heat-Engine Work and Efficiency - Practice 1
For a cyclic engine with no net change in stored energy, work output equals heat input minus rejected heat.
Thermal energysucdg
Connect Heat-Engine Work and Efficiency - Practice 2
For a cyclic engine with no net change in stored energy, work output equals heat input minus rejected heat.
Thermal energysucdh
Spot Changes at the Rocket Pad
Look at two pictures together and describe what changed and what stayed the same.
Visual comparisonsv291
Trace a Swap on a Cargo Grid
Find the changed cells and distinguish a swap from adding new cargo.
Visual comparisonsv392
Compare Two Space-Cargo Grids
Use coordinates to separate a count change, a shape change and a moved item.
Visual comparisonsv491
Audit Changes Without Double Counting
Separate changed cells, changed quantities and changes in object type.
Visual comparisonsv592
What Changed in the Picture? - Practice 1
Point, talk, and try with a trusted adult.
Visual comparisonsvp0b
What Changed in the Picture? - Practice 2
Point, talk, and try with a trusted adult.
Visual comparisonsvp0c
Name a Change in Water State - Practice 1
Track both the starting and ending state.
Water cyclesw2ak
Name a Change in Water State - Practice 2
Track both the starting and ending state.
Water cyclesw2al
Follow Water as It Changes
Connect evaporation, condensation, and precipitation.
Water cyclesw301
Trace Water Along Different Routes
Follow evaporation, condensation, runoff, and infiltration.
Water cyclesw401
Account for Water in a Simple Model - Practice 1
Define the boundary of the model before counting.
Water cyclesw4ba
Account for Water in a Simple Model - Practice 2
Define the boundary of the model before counting.
Water cyclesw4bb
Hygiene: Give Soap Time to Work
Practice the sequence and the scrub time without rushing.
Hygienesy150
Hygiene: Choose Useful Moments
Notice key times for hand care instead of washing without a reason.
Hygienesy250
Hygiene: Cough and Sneeze with Care
Choose a useful response to a cough or sneeze in a fictional situation.
Hygienesy350
Hygiene: Care for All Tooth Surfaces
Use a gentle routine and know when a dental professional can help.
Hygienesy450
Hygiene: Build a Respectful Routine
Choose care that fits a situation without judging people.
Hygienesy550
Hygiene: Keep Food Preparation Separate
Use separation and hand care to prevent cross-contamination.
Hygienesy650
Hygiene: Clean or Disinfect?
Choose the task and product without improvising chemical mixtures.
Hygienesy750
Hygiene: Read a Hand-Sanitizer Label
Distinguish a fallback option from a replacement for every washing situation.
Hygienesy850
Hygiene: Question Microbe Myths
Evaluate broad claims without treating all microbes as enemies.
Hygienesy950
Hygiene: Read Absolute and Relative Differences
Read fictional study rates without turning arithmetic into a medical promise.
Hygienesya50
Hygiene: Separate Measures from Claims
Distinguish a reported behavior, a measured outcome and an inference.
Hygienesyb50
Hygiene: Design a Fair Support Project
Design a school support project without inspecting students or withholding supplies.
Hygienesyc50
Hygiene: Account for Clustered Study Data
Estimate a simple design effect for fictional classroom-level research.
Hygienesyd50
Hygiene: Evaluate Changes Without Overclaiming
Calculate a difference in differences and identify its causal assumptions.
Hygienesye50
Hygiene: Put the Steps in Order
With an adult reading along, put a simple handwashing routine in order.
Hygienesyk50
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