21 加法 28 等于多少？
21 + 28 = 49
21加法28 等于 49
竖式演算
验算
- 用减法验算：49 − 28 = 21
- 用减法验算：49 − 21 = 28
相关题目
21 + 29 = 50
21 + 27 = 48
21 + 30 = 51
21 + 26 = 47
21 + 31 = 52
21 + 25 = 46
21 + 32 = 53
21 + 24 = 45
20 + 28 = 48
22 + 28 = 50
19 + 28 = 47
23 + 28 = 51
24 + 28 = 52
18 + 28 = 46
25 + 28 = 53
17 + 28 = 45
1 + 48 = 49
2 + 47 = 49
3 + 46 = 49
4 + 45 = 49
5 + 44 = 49
6 + 43 = 49
4 + 30 = 34
22 + 60 = 82
36 + 41 = 77
53 + 44 = 97
25 + 54 = 79
46 + 53 = 99
61 - 12 = 49
97 - 48 = 49