Условие:
1. 53+7
2. 84+6
3. 38+3
4. 27+9
5. 18+17
6. 20-8
7. 30-9
8. 30-12
9. 40-17
10. 50-14
11. 100-7
12. 200-6
13. 11-4
14. 15-8
15. 17-9
16. 13-5
17. 26-7
18. 72-8
19. 32-17
20. 53-26
Решение:
\[\boxed{\mathbf{1.}}\]
\[53 + 7 = 60\]
\[\boxed{\mathbf{2.}}\]
\[84 + 6 = 90\]
\[\boxed{\mathbf{3.}}\]
\[38 + 3 = 41\]
\[\boxed{\mathbf{4.}}\]
\[27 + 9 = 36\]
\[\boxed{\mathbf{5.}}\]
\[18 + 17 = 35\]
\[\boxed{\mathbf{6.}}\]
\[20 - 8 = 12\]
\[\boxed{\mathbf{7.}}\]
\[30 - 9 = 21\]
\[\boxed{\mathbf{8.}}\]
\[30 - 12 = 18\]
\[\boxed{\mathbf{9.}}\]
\[40 - 17 = 33\]
\[\boxed{\mathbf{10.}}\]
\[50 - 14 = 36\]
\[\boxed{\mathbf{11.}}\]
\[100 - 7 = 93\]
\[\boxed{\mathbf{12.}}\]
\[200 - 6 = 194\]
\[\boxed{\mathbf{13.}}\]
\[11 - 4 = 7\]
\[\boxed{\mathbf{14.}}\]
\[15 - 8 = 7\]
\[\boxed{\mathbf{15.}}\]
\[17 - 9 = 8\]
\[\boxed{\mathbf{16.}}\]
\[13 - 5 = 8\]
\[\boxed{\mathbf{17.}}\]
\[26 - 7 = 19\]
\[\boxed{\mathbf{18.}}\]
\[72 - 8 = 64\]
\[\boxed{\mathbf{19.}}\]
\[32 - 17 = 15\]
\[\boxed{\mathbf{20.}}\]
\[53 - 26 = 27\]