熟记特殊数字

百化分

1/1 = 100% 1/2 = 50% 1/3 = 33.3% 1/4 = 25% 1/5 = 20% 1/6 = 16.7% 1/7 = 14.3% 1/8 = 12.5% 1/9 = 11.1% 1/10 = 10% 1/11 = 9.1% 1/12 = 8.3% 1/13 = 7.7% 1/14 = 7.1% 1/15 = 6.7% 1/16 = 6.25% 1/17 = 5.9% 1/18 = 5.6% 1/19 = 5.3% 1/20 = 5% 3/8 = 37.5% 5/8 = 62.5% 2/7= 28.6% 3/7= 42.9% 5/6= 83.3%

平方

11*11 = 121 12*12 = 144 13*13 = 169 14*14 = 196 15*15 = 225 16*16 = 256 17*17 = 289 18*18 = 324 19*19 = 361 20*20 = 400 21*21 = 441 22*22 = 484 23*23 = 529 24*24 = 576 25*25 = 625 26*26 = 676 27*27 = 729 28*28 = 784 29*29 = 841 30*30 = 900

多次方

1.05^4 = 1.22 1.1^4 = 1.46 1.15^4 = 1.75 1.2^4 = 2.07