21 减法 20 等于多少？
21 - 20 = 1
21减法20 等于 1
竖式演算
验算
- 用加法验算：1 + 20 = 21
相关题目
21 - 19 = 2
21 - 21 = 0
21 - 18 = 3
21 - 17 = 4
21 - 16 = 5
21 - 15 = 6
21 - 14 = 7
21 - 13 = 8
20 - 20 = 0
22 - 20 = 2
23 - 20 = 3
24 - 20 = 4
25 - 20 = 5
26 - 20 = 6
27 - 20 = 7
28 - 20 = 8
2 - 1 = 1
3 - 2 = 1
4 - 3 = 1
5 - 4 = 1
6 - 5 = 1
7 - 6 = 1
95 - 65 = 30
35 - 32 = 3
90 - 70 = 20
93 - 82 = 11
68 - 2 = 66
89 - 31 = 58
1 × 1 = 1
38 - 35 = 3