Grade
4

Same & Different: Using Arrays to Multiply

Look at the two pictures. What do you notice?

A. shows a rectangle with 4 parts as a model for multiplication. The top left part is 20 times 10. The top right part is 20 times 6. The bottom left part is 4 times 10. The bottom right part is 4 times 6. B. shows a rectangle with 2 parts as a model for multiplication. The vertical side length is 10 for one part and 6 for the other part. The horizontal side length is 24.
  1. How are pictures A and B mathematically the same, and how are they different?
    • A and B are the same because …
    • A and B are different because …
  2. Make a third figure with the dimensions labeled. Explain how your picture is the same as pictures A and B, and how it is different.
Printable Version

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Reference for Educators

Sample problems and solutions