1. Subtraction: Adding UP

2. The whole is a multiple of ten.
Category 1
The whole is a multiple of ten.

3. 20 – – – – 11

4. 20 – – 9 20 – 7 20 – 8

5. 30 – – – – 12

6. 30 – – – – 21

7. 40 – – – – 18

8. 40 – – – – 24

9. 50 – – – – 33

10. 60 – – – – 19

11. 70 – – – – 18

12. The whole is a no longer multiple of ten but is below fifty.
Category 2
The whole is a no longer multiple of ten but is below fifty.

13. 15 – 9

14. 21 – – 9 21 – 7 21 – 8

15. 25 – – – – 9

16. 23 – – – – 9

17. 31 – – – – 15

18. 32 – – – – 15

19. 44 – – – – 25

20. 41 – – – – 19

21. 23 – – – – 18

22. Mixture of numbers that lend themselves to the Adding Up Strategy
Category 3
Mixture of numbers that lend themselves to the Adding Up Strategy

23. 20 – – – – 17

24. 30 – – – – 27

25. 40 – – – – 34

26. 50 – – – – 17

27. 60 – – – – 19

28. 70 – – – – 36

29. 80 – – – – 58

30. 90 – – – – 69

31. 100 – – – – 24