Which One Doesn't Belong? Tenths & Hundredths

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: The fraction 7-tenths. B: The fraction expression 7-tenths + 2-hundredths. C: The decimal 0.72. D: A number line from 70-hundredths to 75-hundredths, with 4 tick marks between them. The second tick mark has a red circle around it and a red arrow pointing to it.


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?