15 加法 21 等于多少？
15 + 21 = 36
15加法21 等于 36
竖式演算
验算
- 用减法验算：36 − 21 = 15
- 用减法验算：36 − 15 = 21
相关题目
15 + 20 = 35
15 + 22 = 37
15 + 19 = 34
15 + 23 = 38
15 + 24 = 39
15 + 18 = 33
15 + 25 = 40
15 + 17 = 32
14 + 21 = 35
16 + 21 = 37
13 + 21 = 34
17 + 21 = 38
12 + 21 = 33
18 + 21 = 39
11 + 21 = 32
19 + 21 = 40
1 + 35 = 36
2 + 34 = 36
3 + 33 = 36
4 + 32 = 36
5 + 31 = 36
6 + 30 = 36
12 + 74 = 86
19 + 70 = 89
16 + 60 = 76
4 + 95 = 99
30 + 31 = 61
49 + 50 = 99
78 - 42 = 36
76 - 40 = 36