Fill in the blanks with the correct number.
1. 4 + 4 = 8 + ___
2. 8 + 2 = 6 + ___
3. 3 + 3 = 1 + ___
4. 10 + 10 = 15 + ___
5. 6 + ___ = 10 + 2
6. 8 + ___ = 9 + 5
7. 8 + 2 = 10 + ___
8. 5 + 3 = 7 + ___
9. 14 + 10 = 10 + ___
10. 9 + 6 = 8 + ___
11. 10 + ___ = 7 + 7
12. 12 + ___ = 10 + 10
13. ___ + 1 = 10 + 2
14. 1 + 9 = ___ + 7
15. 17 + 2 = 15 + ___
16. 16 + 4 = 18 + ___