Trace a Swap on a Cargo Grid

5 questions0m 0s

Learn the skill

Read columns A, B, C from left to right and rows 1, 2 from top to bottom. Compare the same address before and after. A swap changes two locations but preserves the total number of objects.

Worked example

If a star and a circle exchange places, two cells change. There is still one star and one circle, not two extra objects.

Before rows: star, circle, triangle; diamond, square, empty. After rows: circle, star, triangle; diamond, square, empty. Only A1 and B1 change. — Two changed cells; five objects before and after.

The Cargo Swap

Before: A1 star, B1 circle, C1 triangle, A2 diamond, B2 square, C2 empty. After: A1 circle, B1 star, C1 triangle, A2 diamond, B2 square, C2 empty. Each named shape represents one object. Rows run downward. Count changed cells, not the number of differences you can describe in words.

Question 1 Which two cells change? A1 and B1 A2 and B2 B1 and C2

Question 2 How many cells change? Answer

Question 3 How many objects are in the After grid? Answer

Question 4 What happens to the total number of objects? It stays the same It increases by two It decreases by one

Question 5 Where is the star after the swap? B1 A1 C1