Two-Digit Addition & Subtraction — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 47 + 36 = 83.
Add the ones: 7 + 6 = 13, write 3 and carry 1. Add the tens: 4 + 3 + 1 = 8. So 47 + 36 = 83.
2. 82 - 45 = 37.
Since 2 ones is less than 5 ones, regroup 1 ten to get 12 − 5 = 7. Then 7 − 4 = 3 in the tens. So 82 − 45 = 37.
3. 29 + 53 = 82.
Add the ones: 9 + 3 = 12, write 2 and carry 1. Add the tens: 2 + 5 + 1 = 8. So 29 + 53 = 82.
4. 91 - 67 = 24.
Regroup 1 ten so the ones become 11 − 7 = 4. Then 8 − 6 = 2 in the tens. So 91 − 67 = 24.
5. 37 + 38 = 75.
To find the missing addend, subtract: 75 − 38 = 37. Check: 37 + 38 = 75.
6. 63 - 34 = 29.
To find the missing part, subtract the difference from the whole: 63 − 29 = 34. Check: 63 − 34 = 29.
7. 58 + 24 = 82.
Add the ones: 8 + 4 = 12, write 2 and carry 1. Add the tens: 5 + 2 + 1 = 8. So 58 + 24 = 82.
8. 74 - 36 = 38.
Regroup 1 ten so 4 ones become 14: 14 − 6 = 8. Then 6 − 3 = 3 in the tens. So 74 − 36 = 38.
9. 45 + 47 = 92.
Add the ones: 5 + 7 = 12, write 2 and carry 1. Add the tens: 4 + 4 + 1 = 9. So 45 + 47 = 92.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
36 + 48
→ 84
84
95 - 57
→ 38
38
67 + 28
→ 95
95
81 - 46
→ 35
35
Each addition needs regrouping (6+8=14, 7+8=15) and each subtraction needs regrouping (5<7, 1<6). Carry or borrow 1 ten when the ones cannot subtract or sum past 9, then add or subtract the tens to finish.