Subtraction Within 20 (Regrouping) — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 14 - 9 = 5
Count up from 9 to 14: 10, 11, 12, 13, 14 — that is 5 jumps, so 14 - 9 = 5.
2. 11 - 7 = 4
Count up from 7 to 11: 8, 9, 10, 11 — four steps means 11 - 7 = 4.
3. 15 - 6 = 9
Break 6 into 5 and 1: 15 - 5 = 10, then 10 - 1 = 9.
4. 13 - 8 = 5
Split 8 into 3 and 5: 13 - 3 = 10, then 10 - 5 = 5.
5. 17 - 8 = 9
Since 8 + 9 = 17, the number that goes with 8 to reach 17 is 9.
6. 12 - 4 = 8
Take 2 away to get to 10 (12 - 2 = 10), then subtract 2 more to land on 8.
7. 16 - 7 = 9
Break 7 into 6 and 1: 16 - 6 = 10, then 10 - 1 = 9.
8. 18 - 9 = 9
This is a doubles fact; 9 + 9 = 18, so removing one 9 leaves the other 9.
9. 11 - 3 = 8
Take 1 off to hit 10 (11 - 1 = 10), then subtract 2 more to get 8.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
14 - 5
→ 9
9
11 - 6
→ 5
4
13 - 9
→ 3
5
12 - 7
→ 4
3
Pair each subtraction with the answer shown, then check by adding back: 5 + 9 = 14 and 6 + 5 = 11, and count up from the smaller number to the larger to confirm the other two matches.