Grade
2

Which One Doesn’t Belong? Base Ten Pieces

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. shows a 100-grid with 80 units shaded. 2 more pieces each have 20 units, all shaded. The number is written as 120. B. shows 7 tens. The number is written as 70. C. shows 2 100-grids, 1 ten, and 4 ones. The number is written as 214. D. shows 2 100-grids and 5 tens. The number is written as 200 + 50.

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