Subtraction Within 20 (Regrouping) — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What is 12 - 5?
A) 8
B) 6
C) 7
D) 9
Split 5 into 2 and 3: 12 - 2 = 10, then 10 - 3 = 7.
2. What is 16 - 7?
A) 9
B) 8
C) 7
D) 6
Break 7 into 6 and 1: 16 - 6 = 10, then 10 - 1 = 9.
3. What is 11 - 4?
A) 8
B) 6
C) 5
D) 7
Take 1 off to reach 10 (11 - 1 = 10), then subtract 3 more to get 7.
4. What is 14 - 6?
A) 7
B) 9
C) 8
D) 6
Split 6 into 4 and 2: 14 - 4 = 10, then 10 - 2 = 8.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 13 - 7 = 6
Break 7 into 3 and 4: 13 - 3 = 10, then 10 - 4 = 6.
2. 17 - 8 = 9
Since 8 + 9 = 17, taking 8 from 17 must leave 9.
3. 15 - 9 = 6
Count up from 9 to 15: 10, 11, 12, 13, 14, 15 — that is 6 steps.
4. 11 - 6 = 5
Split 6 into 1 and 5: 11 - 1 = 10, then 10 - 5 = 5.
5. 18 - 9 = 9
A doubles fact — 9 + 9 = 18 — means 18 - 9 has to be 9.