21 加法 31 等于多少？
21 + 31 = 52
21加法31 等于 52
竖式演算
验算
- 用减法验算：52 − 31 = 21
- 用减法验算：52 − 21 = 31
相关题目
21 + 30 = 51
21 + 32 = 53
21 + 29 = 50
21 + 33 = 54
21 + 28 = 49
21 + 34 = 55
21 + 35 = 56
21 + 27 = 48
20 + 31 = 51
22 + 31 = 53
19 + 31 = 50
23 + 31 = 54
24 + 31 = 55
18 + 31 = 49
25 + 31 = 56
17 + 31 = 48
1 + 51 = 52
2 + 50 = 52
3 + 49 = 52
4 + 48 = 52
5 + 47 = 52
6 + 46 = 52
60 + 6 = 66
66 + 2 = 68
24 + 23 = 47
11 + 76 = 87
91 + 7 = 98
71 + 15 = 86
94 - 42 = 52
63 - 11 = 52