第1个回答 2010-08-29
弄个表贴在桌子上不就行了 没有简便的方法 除非你会速算
3.14 x 1 = 3.14
3.14 x 2 = 6.28
3.14 x 3 = 9.42
3.14 x 4 = 12.56
3.14 x 5 = 15.7
3.14 x 6 = 18.84
3.14 x 7 = 21.98
3.14 x 8 = 25.12
3.14 x 9 = 28.26
3.14 x 10 = 31.4
3.14 x 11 = 34.54
3.14 x 12 = 37.68
3.14 x 13 = 40.82
3.14 x 14 = 43.96
3.14 x 15 = 47.1
3.14 x 16 = 50.24
3.14 x 17 = 53.38
3.14 x 18 = 56.52
3.14 x 19 = 59.66
3.14 x 20 = 62.8
3.14 x 21 = 65.94
3.14 x 22 = 69.08
3.14 x 23 = 72.22
3.14 x 24 = 75.36
3.14 x 25 = 78.5
3.14 x 26 = 81.64
3.14 x 27 = 84.78
3.14 x 28 = 87.92
3.14 x 29 = 91.06
3.14 x 30 = 94.2