12 加法 9 等于多少？

12 + 9 = 21

12加法9 等于 21

竖式演算

112+921

验算

  • 用减法验算：21 − 9 = 12
  • 用减法验算：21 − 12 = 9

相关题目

12 + 8 = 20 12 + 10 = 22 12 + 11 = 23 12 + 7 = 19 12 + 12 = 24 12 + 6 = 18 12 + 13 = 25 12 + 5 = 17 11 + 9 = 20 13 + 9 = 22 10 + 9 = 19 14 + 9 = 23 15 + 9 = 24 9 + 9 = 18 16 + 9 = 25 8 + 9 = 17 1 + 20 = 21 2 + 19 = 21 3 + 18 = 21 4 + 17 = 21 5 + 16 = 21 6 + 15 = 21 52 + 65 = 117 78 + 8 = 86 57 + 8 = 65 90 + 61 = 151 90 + 96 = 186 39 + 36 = 75 45 - 24 = 21 50 - 29 = 21