Finding Missing Numbers in Number Sentences

Name: _______________________________
Date: _______________________________

Instructions: Find the missing number that makes each number sentence true. Write your answer on the line.

Part A: Addition Number Sentences

1. 5 + _______ = 12
2. _______ + 7 = 15
3. 9 + _______ = 18
4. _______ + 6 = 14
5. 11 + _______ = 20
6. _______ + 4 = 13

Part B: Subtraction Number Sentences

7. 16 - _______ = 9
8. _______ - 5 = 8
9. 20 - _______ = 12
10. _______ - 7 = 6
11. 17 - _______ = 10
12. _______ - 9 = 5

Part C: Mixed Practice

13. 8 + _______ = 17
14. 15 - _______ = 7
15. _______ + 12 = 19
16. _______ - 8 = 11

💡 Tip: Think about what number you need to add or subtract to make the sentence true!