18 加法 21 等于多少？
18 + 21 = 39
18加法21 等于 39
竖式演算
验算
- 用减法验算：39 − 21 = 18
- 用减法验算：39 − 18 = 21
相关题目
18 + 20 = 38
18 + 22 = 40
18 + 19 = 37
18 + 23 = 41
18 + 24 = 42
18 + 18 = 36
18 + 25 = 43
18 + 17 = 35
17 + 21 = 38
19 + 21 = 40
20 + 21 = 41
16 + 21 = 37
21 + 21 = 42
15 + 21 = 36
22 + 21 = 43
14 + 21 = 35
1 + 38 = 39
2 + 37 = 39
3 + 36 = 39
4 + 35 = 39
5 + 34 = 39
6 + 33 = 39
40 + 100 = 140
13 + 33 = 46
45 + 22 = 67
22 + 7 = 29
19 + 80 = 99
44 + 30 = 74
88 - 49 = 39
80 - 41 = 39