一、在□里填合适的数。□ - 70 = 25
□ + 9 = 24
□ + 80 = 98
2 + □ = 70
□ - 9 = 80
75 - □ = 55
10 + □ = 69
2 + □ = 90
□ + 8 = 26
□ - 70 = 8
□ - 40 = 33
□ + 10 = 27
40 + □ = 74
□ + 4 = 31
□ - 6 = 53
□ - 20 = 5
59 - □ = 52
□ + 30 = 67
□ + 6 = 45 - 5
39 - □ = 18 - 9
□ - 5 = 70 + 18
50 - 4 = 40 + □
□ + 80 = 95 - 6
□ - 8 = 32 + 7
14 - □ = 55 - 50
41 - □ = 62 - 30
47 + 7 = □ - 7
58 + 30 - □ = 80
91 - 30 - □ = 52
32 - 6 - □ = 20

95,15,18,68,89,20,59,88,18,78,73,17,34,27,59,25,7,37,34,30,93,6,9,47,9,9,61,8,9,6

1. □ - 70 = 25，□ = 25 + 70 = 95
2. □ + 9 = 24，□ = 24 - 9 = 15
3. □ + 80 = 98，□ = 98 - 80 = 18
4. 2 + □ = 70，□ = 70 - 2 = 68
5. □ - 9 = 80，□ = 80 + 9 = 89
6. 75 - □ = 55，□ = 75 - 55 = 20
7. 10 + □ = 69，□ = 69 - 10 = 59
8. 2 + □ = 90，□ = 90 - 2 = 88
9. □ + 8 = 26，□ = 26 - 8 = 18
10. □ - 70 = 8，□ = 8 + 70 = 78
11. □ - 40 = 33，□ = 33 + 40 = 73
12. □ + 10 = 27，□ = 27 - 10 = 17
13. 40 + □ = 74，□ = 74 - 40 = 34
14. □ + 4 = 31，□ = 31 - 4 = 27
15. □ - 6 = 53，□ = 53 + 6 = 59
16. □ - 20 = 5，□ = 5 + 20 = 25
17. 59 - □ = 52，□ = 59 - 52 = 7
18. □ + 30 = 67，□ = 67 - 30 = 37
19. □ + 6 = 45 - 5，45 - 5 = 40，□ = 40 - 6 = 34
20. 39 - □ = 18 - 9，18 - 9 = 9，□ = 39 - 9 = 30
21. □ - 5 = 70 + 18，70 + 18 = 88，□ = 88 + 5 = 93
22. 50 - 4 = 40 + □，50 - 4 = 46，□ = 46 - 40 = 6
23. □ + 80 = 95 - 6，95 - 6 = 89，□ = 89 - 80 = 9
24. □ - 8 = 32 + 7，32 + 7 = 39，□ = 39 + 8 = 47
25. 14 - □ = 55 - 50，55 - 50 = 5，□ = 14 - 5 = 9
26. 41 - □ = 62 - 30，62 - 30 = 32，□ = 41 - 32 = 9
27. 47 + 7 = □ - 7，47 + 7 = 54，□ = 54 + 7 = 61
28. 58 + 30 - □ = 80，58 + 30 = 88，□ = 88 - 80 = 8
29. 91 - 30 - □ = 52，91 - 30 = 61，□ = 61 - 52 = 9
30. 32 - 6 - □ = 20，32 - 6 = 26，□ = 26 - 20 = 6