1 加法 20 等于多少？

1 + 20 = 21

1加法20 等于 21

竖式演算

1+2021

验算

  • 用减法验算：21 − 20 = 1
  • 用减法验算：21 − 1 = 20

相关题目

1 + 19 = 20 1 + 21 = 22 1 + 22 = 23 1 + 18 = 19 1 + 23 = 24 1 + 17 = 18 1 + 24 = 25 1 + 16 = 17 2 + 20 = 22 3 + 20 = 23 4 + 20 = 24 5 + 20 = 25 6 + 20 = 26 7 + 20 = 27 8 + 20 = 28 9 + 20 = 29 2 + 19 = 21 3 + 18 = 21 4 + 17 = 21 5 + 16 = 21 6 + 15 = 21 7 + 14 = 21 31 + 37 = 68 76 + 12 = 88 23 + 31 = 54 15 + 100 = 115 13 + 100 = 113 2 + 91 = 93 83 - 62 = 21 100 - 79 = 21