Grade
4

Which One Doesn't Belong? Rectangle Relationships

Look at this set of four pictures. Decide which one doesn’t belong with the other three. Use math words to describe your thinking. There are many ways to think about each one!

A: An open array with 2-digit dimensions. The side dimension is labeled 20 and 2. The top dimension are labeled 10 and 8. B: An open array with 2-digit dimensions. The side dimension is not labeled. The top dimension is labeled 30 and 6. Area = 432 square units. C: An array of base ten pieces with 2-digit dimensions. The side dimension is labeled 20 and 7. The top dimension is labeled 10 and 6. D: An open array with 1- and 2-digit dimensions. The side dimension is labeled 8. The top dimension is labeled 50 and 4.

Challenge

Find reasons why each number might not belong with the other three.

Share

Explain your thinking to someone. Do they have different reasons one doesn't belong?

Printable Version

Google doc for printing and copying

Reference for Educators

Sample problems and solutions