1. SIX SUBTRACTION
STRATEGIES

2. #1 Round the Subtrahend to a Multiple of 10 and Adjust:
63 – 28 =
63 – 30 = 33
= 35

3. #1 Round the Subtrahend to a Multiple of 10 and Adjust:
81 – 47 =

4. #2 Decompose the Subtrahend
63 – 20 = 43
43 – 3 = 40
40 – 5 = 35

5. #2 Decompose the Subtrahend Another Way
63 – 3 = 60
60 – 20 = 40
40 – 5 = 35

6. #2 Decompose the Subtrahend
81 – 49 =

7. #3 Add Instead
= 58
= 60
= 30
= 35

8. = 35
+ 30
+ 2
+ 3 58 60 63 28

9. #3 Add Instead 2nd Way
= 30
= 60
= 30
= 35

10. = 35
+ 2
+ 30
+ 3 30 60 63 28

11. #3 Add Instead

12. #4 Same Difference
+ 2
+ 2 30 65
+ 2
+ 2 28 63

13. #4 Same Difference
+ 2
+ 2 35 30 65
+ 2
+ 2 28 63

14. #4 Same Difference
- 1
- 1 63 36 99
- 1
- 1 37
100

15. - 63 – 28 40 – 5 = 35 #5 Break Apart by Place (Start on the Left) 6 3
2 8 40
- 5
40 – 5 = 35

16. #5 Break Apart by Place (Start on the Left)

17. #5 Break Apart by Place (Start on the Left)

18. - 63 - 28 35 #6 Standard Algorithm Change 63 into
5 tens or 50 and 13 ones 5 13 35 -
6 3
2 8

19. #6 Standard Algorithm
17 - 9 17 8 17 - 9