Which One Doesn’t Belong? Sets of Shapes

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: 2 green circles, one slightly larger than the other. B: A blue cylinder on top of a green cylinder. The cylinders are the same size. C: 3 green spheres, all the same size. D: 2 green cones, both the same size. 1 points to the side and 1 points up.


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


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