1. Making Landmark or Friendly Numbers

2. Category 1
Single digit numbers that are one away from landmark/friendly number

3. 10 + 2
9 + 2
9 + 5
9 + 8
9 + 9

4. 20 + 5
19 + 5
19 + 7
19 + 8

5. 19 + 1

6. 29 + 1
29 + 5

7. 40 + 4
39 + 4

8. 49 + 1
49 + 8

9. 60 + 7
59 + 7

10. 70 + 8
69 + 8

11. 80 + 4
79 + 4

12. 20 + 5
19 + 5
19 + 7
19 + 8

13. Category 2
One addend is 2 away from a multiple of ten or landmark/friendly number.

14. 10 + 5
8 + 5
8 + 7
8 + 12

15. 8 + 2
8 + 14
8 + 25
8 + 36

16. 18 + 2

17. 30 + 5
28 + 5
28 + 7

18. 40 + 4
38 + 4

19. 50 + 6
48 + 6

20. 60 + 3
58 + 3

21. 70 + 7
68 + 7

22. 80 + 5
78 + 5

23. Category 3
Both addends are one or more away from a multiple of ten or landmark/friendly number.

24.
9 + 19
9 + 29
9 + 39

25.
9 + 18
9 + 28