DD. True or False
- 6 + 7 = 6 + 6 + 1 __________________
- 7 + 8 = 7 + 7 − 1 __________________
- 10 + 9 = 10 + 10 − 1 __________________
- 15 − 8 = 8 __________________
- 13 − 1 = 6 + 6 __________________
- 8 + 8 = 18 − 2 __________________
- 16 − 1 = 7 + 7 __________________
- 19 − 9 = 9 __________________
- Explain how you know your answer to Question C is correct.