Subtraction Games that teach the strategy:
Anytime you are subtracting a teen from with the same value in the ones place you will always get 10. For example, 12-2=10; 15-5=10;, 19-9=10. This is pretty simple and often just needs to be explained.
1. Leave 10: Put 30 of the same objects (we use peanuts) on a table. Each player grabs 1- 3 objects on their turn. The goal is to be the last player that leaves 10 objects on the table.
2. Draw a number line 1- 20 on the sidewalk or use tape to make one inside. Call out a teen number and have your child stand on it. Now subtract the number in the ones place, and have your child jump to that number. How much is left? Have your child call out the numbers and you take a turn on the number line.
For example, I call out 17 (child stands on 17). I say " subtract 7" then the child walks down the number line subtracting 7. Of course they should always land on 10.
3.Use the 100 Chart: Have your child find a teen number and then subtract the number in the ones place from the original number. What number do you land on every time?
For example, put your finger on 14, subtract 4.
-This is almost as easy as adding and subtracting 0. My sons both got this strategy by the end of jumping on the number line They are so proud of themselves for learning the "teen trick". I love the fact that their confidence is building. -Suzanne
- I agree with Suzanne. My daughter thinks that she is just not good at math. She defeats herself before she even tries. I am going to do more of these "easier" strategies with her to build up her confidence. I have always been good at math so, it has been hard for me to see her struggle. - Eliza