一、口算。
55 - 50 =
62 + 30 =
12 - 9 =
68 + 7 =
91 - 7 =
75 - 7 =
88 - 20 =
48 + 2 =
35 - 6 =
4 + 57 =
72 + 20 =
2 + 16 =
69 - 40 =
5 + 57 =
55 - 3 =
37 + 6 =
52 - 6 =
23 + 70 =
64 - 6 =
71 + 7 =
66 + 20 =
28 + 8 =
47 - 20 =
69 - 20 =
57 + 3 =
33 - 8 =
72 - 6 =
84 - 7 =
74 + 9 =
40 + 15 =

1. 55-50=5
2. 62+30=92
3. 12-9=3
4. 68+7=75
5. 91-7=84
6. 75-7=68
7. 88-20=68
8. 48+2=50
9. 35-6=29
10. 4+57=61
11. 72+20=92
12. 2+16=18
13. 69-40=29
14. 5+57=62
15. 55-3=52
16. 37+6=43
17. 52-6=46
18. 23+70=93
19. 64-6=58
20. 71+7=78
21. 66+20=86
22. 28+8=36
23. 47-20=27
24. 69-20=49
25. 57+3=60
26. 33-8=25
27. 72-6=66
28. 84-7=77
29. 74+9=83
30. 40+15=55

二、看图写算式。

乘法算式：□×□=□ 乘法算式：□×□=□
或 □×□=□ 或 □×□=□

3×4=12
4×3=12
5×3=15
3×5=15