Two-Digit Addition & Subtraction — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What is 64 + 29?
A) 83
B) 93
C) 82
D) 73
Add the ones: 4 + 9 = 13, write 3 and carry 1. Add the tens: 6 + 2 + 1 = 9. So 64 + 29 = 93.
2. When you subtract 52 - 37, how many ones does the tens place lend?
A) 1
B) 10
C) 5
D) 7
Since 2 ones cannot subtract 7 ones, the tens place lends 1 ten. One ten always equals 10 ones, which then become 12 ones to allow 12 − 7 = 5.
3. Which equation is true?
A) 46 + 35 = 71
B) 58 + 24 = 82
C) 73 - 29 = 54
D) 67 - 38 = 39
Check by adding: 8 + 4 = 12, write 2 and carry 1. Then 5 + 2 + 1 = 8. The sum 82 matches, so this equation is true.
4. What is 81 - 47?
A) 44
B) 36
C) 34
D) 46
Regroup 1 ten so 1 one becomes 11: 11 − 7 = 4. Then 7 − 4 = 3 in the tens. So 81 − 47 = 34.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 59 + 34 = 93.
Add the ones: 9 + 4 = 13, write 3 and carry 1. Add the tens: 5 + 3 + 1 = 9. So 59 + 34 = 93.
2. 72 - 48 = 24.
Regroup 1 ten so 2 ones become 12: 12 − 8 = 4. Then 6 − 4 = 2 in the tens. So 72 − 48 = 24.
3. 38 + 55 = 93.
Add the ones: 8 + 5 = 13, write 3 and carry 1. Add the tens: 3 + 5 + 1 = 9. So 38 + 55 = 93.
4. 93 - 65 = 28.
Regroup 1 ten so 3 ones become 13: 13 − 5 = 8. Then 8 − 6 = 2 in the tens. So 93 − 65 = 28.
5. 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.