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Chance Lab
The bag has tiles, not a crystal ball.
Seven investigations. Count groups, read fractions, predict and compare.
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Two-draw paths
Observation board
Every draw in this run
| Draw | Stars / tiles | Result |
|---|
Your chance discoveries
Fun fact: Two stars in four tiles and twenty stars in forty tiles give the same starting star chance when every tile is equally likely.
Continue with Grade 7 practice: Count and compare tile chances · Track chances after a draw. Or print tile-chance practice and return-or-keep practice.
Watch: Count tiles, compare chances or Return a tile or leave it out.
After investigation 7: watch Count two-draw paths, try two-draw practice, or print paths with returns and paths without returns.
Go further: Watch Choose the Condition · Print conditional-probability practice. These introduce choosing a smaller condition group.
About this probability model
Each individual tile is equally likely. Returned tiles restore the bag before each draw. Kept-out tiles are removed. Runs use fresh browser random draws; results are not adjusted to match a target ratio. This is a teaching model, not a prediction of real-world fairness. There is no betting, money or reward for a lucky result. Restarting discards the current investigation's displayed observations.
OpenStax: probability and observed results · OpenStax: independent events