20 加法 21 等于多少？
20 + 21 = 41
20加法21 等于 41
竖式演算
验算
- 用减法验算：41 − 21 = 20
- 用减法验算：41 − 20 = 21
相关题目
20 + 20 = 40
20 + 22 = 42
20 + 19 = 39
20 + 23 = 43
20 + 24 = 44
20 + 18 = 38
20 + 25 = 45
20 + 17 = 37
19 + 21 = 40
21 + 21 = 42
22 + 21 = 43
18 + 21 = 39
23 + 21 = 44
17 + 21 = 38
24 + 21 = 45
16 + 21 = 37
1 + 40 = 41
2 + 39 = 41
3 + 38 = 41
4 + 37 = 41
5 + 36 = 41
6 + 35 = 41
70 + 1 = 71
23 + 33 = 56
100 + 4 = 104
10 + 49 = 59
2 + 47 = 49
43 + 55 = 98
98 - 57 = 41
52 - 11 = 41