Two-Digit Addition & Subtraction — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 43 has 4 tens and 3 ones.
In the number 43, the digit 4 is in the tens place, so there are 4 tens. The digit 3 is in the ones place.
2. 5 tens and 7 ones make the number 57.
5 tens = 50, plus 7 ones = 7. So 50 + 7 = 57.
3. 38 + 40 = 78.
Add the ones: 8 + 0 = 8. Add the tens: 3 + 4 = 7. So 38 + 40 = 78.
4. 92 − 50 = 42.
Subtract the ones: 2 − 0 = 2. Subtract the tens: 9 − 5 = 4. So 92 − 50 = 42.
5. 26 + 15 = 41.
Add the ones: 6 + 5 = 11, write 1 and carry 1. Add the tens: 2 + 1 + 1 = 4. So 26 + 15 = 41.
6. In 84, the digit 8 stands for 80.
The digit 8 is in the tens place, so it represents 8 tens, which equals 80.
7. 70 − 28 = 42.
Regroup: 10 − 8 = 2 in the ones place, then 6 − 2 = 4 in the tens place. So 70 − 28 = 42.
8. 38 + 33 = 71.
To find the missing number, subtract: 71 − 33 = 38. Check: 38 + 33 = 71.
9. 55 − 19 = 36.
Regroup: 15 − 9 = 6 in the ones place, then 4 − 1 = 3 in the tens place. So 55 − 19 = 36.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Tom had 45 cards and got 27 more.
→ 38 + 44 = 82
45 + 27 = 72
Sara had 82 stickers and gave away 35.
→ 45 + 27 = 72
82 − 35 = 47
A jar has 38 red beads and 44 blue beads.
→ 91 − 56 = 35
38 + 44 = 82
Jake had 91 coins and spent 56.
→ 82 − 35 = 47
91 − 56 = 35
Tom got more cards, so you add: 45 + 27 = 72. Sara gave away stickers, so you subtract: 82 − 35 = 47. The jar has two groups of beads to combine: 38 + 44 = 82. Jake spent coins, so you subtract: 91 − 56 = 35.