Missing Numbers in Addition Sentences

Name: _______________________________

Date: _______________________________

Instructions: Find the missing number in each addition sentence. Show your working.

Part A: Missing numbers at the end

1. 5 + 3 = ________

2. 12 + 7 = ________

3. 8 + 6 = ________

4. 15 + 9 = ________

5. 23 + 16 = ________

6. 34 + 28 = ________

Part B: Missing numbers at the beginning

7. ________ + 4 = 11

8. ________ + 8 = 15

9. ________ + 5 = 18

10. ________ + 12 = 25

11. ________ + 17 = 40

12. ________ + 23 = 56

Part C: Missing numbers in the middle

13. 6 + ________ = 13

14. 9 + ________ = 17

15. 14 + ________ = 22

16. 18 + ________ = 31

17. 25 + ________ = 48

18. 37 + ________ = 65

Part D: Challenge problems

19. 15 + ________ + 8 = 35

20. ________ + 12 + 7 = 30

21. 9 + 16 + ________ = 40

22. ________ + ________ = 24 (Find two numbers that add to 24)

💡 Hint: To find a missing number, use subtraction! If 7 + ? = 15, then ? = 15 - 7