Same & Different: Book by Book

Look at the two pictures. What do you notice?

A. shows Danneh's bookshelf, which has 4 rows of 2 cubbies to hold books. The left cubbies have 45 books in all and the right cubbies have 36 books in all. 45 + 36 = d. B. shows Jason's bookshelf, which has 3 rows of 3 cubbies to hold books. Each cubby holds 9 books. 9 times 9 = j.

  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 picture that shows books on a shelf. Explain how your picture is the same as pictures A and B, and how it is different.