21 加法 30 等于多少？
21 + 30 = 51
21加法30 等于 51
竖式演算
验算
- 用减法验算：51 − 30 = 21
- 用减法验算：51 − 21 = 30
相关题目
21 + 29 = 50
21 + 31 = 52
21 + 28 = 49
21 + 32 = 53
21 + 33 = 54
21 + 27 = 48
21 + 34 = 55
21 + 26 = 47
20 + 30 = 50
22 + 30 = 52
19 + 30 = 49
23 + 30 = 53
24 + 30 = 54
18 + 30 = 48
25 + 30 = 55
17 + 30 = 47
1 + 50 = 51
2 + 49 = 51
3 + 48 = 51
4 + 47 = 51
5 + 46 = 51
6 + 45 = 51
86 + 1 = 87
29 + 20 = 49
51 + 48 = 99
100 + 98 = 198
52 + 15 = 67
77 + 20 = 97
52 - 1 = 51
57 - 6 = 51