As we are working on our addition problems we are paying a lot of attention to whether or not we need to regroup. We are also taking this opportunity to review what the students learned in 1st grade about solving addition problems. There were three strategies that the 1st graders' learned last year.
1. Counting Up
Start with the biggest number and count up the number you are adding to it. You can use this strategy when you are solving any problem, but it is not always the fastest or most efficient way to solve a problem.
2. Double or Doubles +1
In first grade they should have learned their doubles facts from 1+1 to 10+10. I am noticing that several students are still struggling with 6+6, 7+7, 8+8, and 9+9. We can also use our double problems to solve problems that are close to double. If I know 7+7, then I can use that to help me with 7+8 or 8+7.
3. Making Ten
If you are adding something to a 8 or a 9 it is easy use the other number to help you make a ten. If I am adding 9+5= I can borrow 1 from the 5 to make a 10. That would leave me with 4 that I didn't use from the 5. That 10 and 4 leftover ones makes 14.
While you are working on addition homework at home make sure you are asking your 2nd grader what addition strategy did they use and why they chose to use that strategy.
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