Subtracting within 20

Count back, or take away to 10 first.

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

What children learn in Level 27

To take away a little, count back. 17 minus 2: 16, 15.
To take away more, get to 10 first. 14 minus 6: take away 4 to get to 10. Then take away 2 more. 10 minus 2 is 8.
Your turn! Hop from 13 to 10, then take away 2 more.
Taking away 10 from a teen number is quick: 16 minus 10 leaves the 6 ones.
Count back a little, or take away to 10 first.

Georgia's K-12 Mathematics Standards:

1.NR.2.1 — Use a variety of strategies to solve addition and subtraction problems within 20.