19 加法 21 等于多少？
19 + 21 = 40
19加法21 等于 40
竖式演算
验算
- 用减法验算：40 − 21 = 19
- 用减法验算：40 − 19 = 21
相关题目
19 + 20 = 39
19 + 22 = 41
19 + 19 = 38
19 + 23 = 42
19 + 24 = 43
19 + 18 = 37
19 + 25 = 44
19 + 17 = 36
20 + 21 = 41
18 + 21 = 39
21 + 21 = 42
17 + 21 = 38
22 + 21 = 43
16 + 21 = 37
23 + 21 = 44
15 + 21 = 36
1 + 39 = 40
2 + 38 = 40
3 + 37 = 40
4 + 36 = 40
5 + 35 = 40
6 + 34 = 40
81 + 72 = 153
91 + 62 = 153
83 + 36 = 119
80 + 56 = 136
97 + 62 = 159
64 + 81 = 145
84 - 44 = 40
42 - 2 = 40