Grade
3

Which One Doesn't Belong? Sorting Stamps

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: 4 rows of 4 stamps, each 2 cents. B: 4 rows of 3 stamps, each 4 cents. C: 2 rows of 4 stamps, each 4 cents. D: 4 rows of 4-cent stamps. The first row has 3 stamps, the second row has 2, the third row has 1, and the fourth row has 2 stamps.

Challenge

See if you can find reasons why each of the pictures might not belong with the other three.

Share

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

Printable Version

Google doc for printing and copying

Reference for Educators

Sample problems and solutions