Two-Digit Addition & Subtraction — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 53 + 29 = 82.
Add the ones: 3 + 9 = 12, write 2 and carry 1. Add the tens: 5 + 2 + 1 = 8. So 53 + 29 = 82.
2. 86 - 48 = 38.
Regroup 1 ten: 16 − 8 = 8 in the ones, then 7 − 4 = 3 in the tens. So 86 − 48 = 38.
3. 37 + 45 = 82.
Add the ones: 7 + 5 = 12, write 2 and carry 1. Add the tens: 3 + 4 + 1 = 8. So 37 + 45 = 82.
4. 72 - 36 = 36.
Regroup 1 ten so 2 ones become 12: 12 − 6 = 6. Then 6 − 3 = 3 in the tens. So 72 − 36 = 36.
5. 27 + 57 = 84.
To find the missing addend, subtract: 84 − 57 = 27. Check: 27 + 57 = 84.
6. 91 - 38 = 53.
To find the missing part, subtract the difference from the whole: 91 − 53 = 38. Check: 91 − 38 = 53.
7. 64 + 28 = 92.
Add the ones: 4 + 8 = 12, write 2 and carry 1. Add the tens: 6 + 2 + 1 = 9. So 64 + 28 = 92.
8. 80 - 47 = 33.
Regroup 1 ten so 0 ones become 10: 10 − 7 = 3. Then 7 − 4 = 3 in the tens. So 80 − 47 = 33.
9. 46 + 35 = 81.
Add the ones: 6 + 5 = 11, write 1 and carry 1. Add the tens: 4 + 3 + 1 = 8. So 46 + 35 = 81.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
43 + 39
→ 82
82
92 - 58
→ 34
34
55 + 18
→ 73
73
70 - 33
→ 37
37
Each addition has ones that sum past 9 (3+9=12 and 5+8=13), so carry 1 to the tens. Each subtraction has not-enough ones (2<8 and 0<3), so borrow 1 ten before subtracting both columns.