Which One Doesn’t Belong? Base Ten Operations

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!

Each picture shows base ten pieces. A. 2 hundreds, 3 tens and 2 ones plus 2 tens and 2 ones. B. 1 hundred, 6 tens, and 2 ones plus 6 tens and 2 ones. C. 12 tens and 2 ones plus 13 tens and 2 ones. D. 3 hundreds, 3 tens & 4 ones minus 8 tens.


See if you can 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?