Grade
K

Which One Doesn’t Belong? Tiny Triangles

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: 10 blue triangles and 6 green triangles. 10 + 6 = 16. (The number 10 is red in the equation). B: 10 green triangles and 7 yellow squares. 10 (in red) + 7 = 17. C: 10 green triangles and 3 purple triangles.10 (in red) + 3 = 16. D: 9 orange triangles and 6 green triangles. 9 + 6 = 15.

Challenge

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

Seesaw Version

Activity for the Seesaw platform

Reference for Educators

Sample problems and solutions