21 加法 18 等于多少？
21 + 18 = 39
21加法18 等于 39
竖式演算
验算
- 用减法验算：39 − 18 = 21
- 用减法验算：39 − 21 = 18
相关题目
21 + 17 = 38
21 + 19 = 40
21 + 20 = 41
21 + 16 = 37
21 + 21 = 42
21 + 15 = 36
21 + 22 = 43
21 + 14 = 35
20 + 18 = 38
22 + 18 = 40
19 + 18 = 37
23 + 18 = 41
24 + 18 = 42
18 + 18 = 36
25 + 18 = 43
17 + 18 = 35
1 + 38 = 39
2 + 37 = 39
3 + 36 = 39
4 + 35 = 39
5 + 34 = 39
6 + 33 = 39
27 + 2 = 29
84 + 14 = 98
91 + 4 = 95
12 + 35 = 47
20 + 70 = 90
1 + 81 = 82
56 - 17 = 39
53 - 14 = 39