17 加法 21 等于多少？
17 + 21 = 38
17加法21 等于 38
竖式演算
验算
- 用减法验算：38 − 21 = 17
- 用减法验算：38 − 17 = 21
相关题目
17 + 20 = 37
17 + 22 = 39
17 + 19 = 36
17 + 23 = 40
17 + 24 = 41
17 + 18 = 35
17 + 25 = 42
17 + 17 = 34
16 + 21 = 37
18 + 21 = 39
15 + 21 = 36
19 + 21 = 40
20 + 21 = 41
14 + 21 = 35
21 + 21 = 42
13 + 21 = 34
1 + 37 = 38
2 + 36 = 38
3 + 35 = 38
4 + 34 = 38
5 + 33 = 38
6 + 32 = 38
60 + 39 = 99
66 + 3 = 69
43 + 22 = 65
85 + 100 = 185
4 + 45 = 49
10 + 13 = 23
49 - 11 = 38
66 - 28 = 38