Grade
2

Which One Doesn't Belong? Jumping on the Number Line

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: 52 plus 15. A number line shows 52 with a jump forward of 10 to blank and a jump forward of five to blank. B: 82 minus 15. A number line shows 82 with a jump back of 2 to blank, a jump back of 10 to blank, and a jump back of 3 to blank. C: 78 minus 15. A number line shows 78 with a jump back of 10 to blank and a jump back of 5 to blank. D: 86 minus 19. A number line shows 86 with a jump back of 20 to blank and a jump forward of 1 to blank.

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

Reference for Educators

Sample problems and solutions