11~20的加减法+20以内加法（进位） 计算题
1.15 - 8 = 23
2.17 + 7 = 24
3.11 + 10 = 21
4.20 + 1 = 21
5.12 + 7 = 19
6.17 + 7 = 10
7.13 + 9 = 22
8.18 + 6 = 12
9.15 + 2 = 17
10.19 + 8 = 27
11.14 + 2 = 16
12.15 + 5 = 20
13.11 - 2 = 13
14.14 - 1 = 13
15.12 + 9 = 21
16.19 + 9 = 28
17.15 + 10 = 25
18.15 - 5 = 20
19.17 + 2 = 19
20.19 + 7 = 26
21.15 + 3 = 18
22.18 - 7 = 11
23.15 - 9 = 24
24.14 - 1 = 15
25.15 - 8 = 23
26.12 + 5 = 17
27.20 - 3 = 23
28.13 - 8 = 5
29.13 + 9 = 22
30.12 + 1 = 11
31.14 + 4 = 18
32.13 - 8 = 5
33.16 + 4 = 20
34.18 - 1 = 17
35.14 + 5 = 19
36.18 + 1 = 17
37.17 - 9 = 8
38.11 + 5 = 16
39.17 + 5 = 12