Addition and subtraction within 20
The question
19 − 11
11=10+1
19−10=9
9−1=8
- 19 − 11, across the line. Split only the 11 — the amount being taken away — and take it off in two goes.
- The tens first: 19 − 10 = 9.
- Then the ones off what is left: 9 − 1 = 8.
How it works.
- 01
19 − 11, across the line. Split only the 11 — the amount being taken away — and take it off in two goes.
- 02
The tens first: 19 − 10 = 9.
- 03
Then the ones off what is left: 9 − 1 = 8.