7 加法 21 等于多少？

7 + 21 = 28

7加法21 等于 28

竖式演算

7+2128

验算

  • 用减法验算：28 − 21 = 7
  • 用减法验算：28 − 7 = 21

相关题目

7 + 20 = 27 7 + 22 = 29 7 + 19 = 26 7 + 23 = 30 7 + 24 = 31 7 + 18 = 25 7 + 25 = 32 7 + 17 = 24 6 + 21 = 27 8 + 21 = 29 5 + 21 = 26 9 + 21 = 30 4 + 21 = 25 10 + 21 = 31 11 + 21 = 32 3 + 21 = 24 1 + 27 = 28 2 + 26 = 28 3 + 25 = 28 4 + 24 = 28 5 + 23 = 28 6 + 22 = 28 31 + 17 = 48 6 + 41 = 47 53 + 45 = 98 61 + 7 = 68 42 + 33 = 75 60 + 7 = 67 29 - 1 = 28 35 - 7 = 28