X
Use DPP item M to practice the addition facts in Group E.
Discuss students' strategies
including reasoning from known
facts. Using ten and using doubles
are also efficient strategies.
- 13
- 12
- 13
- 13
- 12
- 12
- 12
- 11
Possible response:
2 + 10 = 12. 3 is one more than 2
and 9 is one less than 10, so
2 + 10 is equal to 3 + 9.