21 减法 1 等于多少？

21 - 1 = 20

21减法1 等于 20

竖式演算

21-120

验算

  • 用加法验算：20 + 1 = 21

相关题目

21 - 2 = 19 21 - 3 = 18 21 - 4 = 17 21 - 5 = 16 21 - 6 = 15 21 - 7 = 14 21 - 8 = 13 21 - 9 = 12 20 - 1 = 19 22 - 1 = 21 19 - 1 = 18 23 - 1 = 22 24 - 1 = 23 18 - 1 = 17 25 - 1 = 24 17 - 1 = 16 22 - 2 = 20 23 - 3 = 20 24 - 4 = 20 25 - 5 = 20 26 - 6 = 20 27 - 7 = 20 26 - 1 = 25 79 - 68 = 11 69 - 36 = 33 58 - 2 = 56 23 - 10 = 13 69 - 4 = 65 1 + 19 = 20 9 + 11 = 20