Count Back - Subtracting 1, 2, and 3 are count backs. When subtracting, whisper the larger number in your head and “count back.”
Example: 8 - 3, whisper 8 and count back 7, 6, 5. The difference is 5.
Ten Facts - Subtracting from 10 are ten facts.
Example: 10-7=3 because 7+3=10 Ten facts are just memorized.
Double Facts - Knowing doubles facts helps you. Just the reverse them in subtraction.
Example: 12-6=6 because 6+6=12
Zero Facts - When you subtract zero rom any number, the difference is always the original number you started with.
Example: 9-0=9
Count Up - When subtracting two numbers that are close together on the number line, say the smaller number and count up to the larger number.
Example: 9-6, whisper 6 and count up (7, 8, 9) to 9. The difference is 3.
Fact Families - Fact families are four related facts that are made with the same set of numbers. Example: 14, 6, and 8 can make 6+8=14, 8+6=14, 14-6=8, and 14-8=6
Therefore if subtracting 14-6= __, you can think 6+ 8 =14. The difference is 8.
Magic 9 - This is a gimmick strategy that only works when you subtract 9.
Example: 17-9, add the 1 and 7 of the 17 together to get 8. That is the difference.
Count Up Plus - This is my FAVORITE STRATEGY! When subtracting teen numbers that other strategies don ʼ t work well to solve try it. It involves two steps; getting to ten and then adding the ones.
Example: Start with the 8 and count up to get a ten (2). Then add the ones(4).
Add these, 2+4=6, the difference is 6.
14
- 8
2
You can see how important knowing the ten facts is for this strategy to work for kids.
8+2, 6+4, 7+3, 9+1
15
- 8
2
14
- 6
4
12
- 7
3
17
- 9
1