What are some ways you can find the sum of 3 addends?
Answers vary.
What is the sum of problem A?
10
What is the sum of problem B?
18
Count on to find the sum of 12+2.
13, 14
How can you use counting back to find the difference of 14-3?
Possible answer: I can start at 14. Then I can count back 3: 13, 12, and 11.
How can you use doubles plus 1 to find the sum of 7+8?
7+7+1=15
How can you use a doubles fact to find the sum of 9+11?
9+9+2=20