Think Addition to Subtract

Solve 13 − 8 by asking "8 plus what makes 13?"

Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.

What children learn in Level 5

Here's a secret: every take-away problem has an adding problem hiding inside it!
To solve 13 minus 8, ask: 8 plus what makes 13?
Count up from 8. 2 more gets to 10. Then 3 more gets to 13. That's 5 in all.
So 13 minus 8 is 5!
Your turn: 12 minus 9. Start at 9 and tap to count up to 12. Stop at 10 on the way!
9 plus 3 is 12, so 12 minus 9 is 3. Counting up works best when the two numbers are close together.

Georgia's K-12 Mathematics Standards:

2.NR.2.1 — Fluently add and subtract within 20 using a variety of mental, part-whole strategies.