几个数学简便算法

题目

几个数学简便算法
用简便方法计算
1.25X0.32
0.56X2.5
14.28÷0.7X2.56
1.57X6.4+3.6X1.57
10÷0.1X9.05-26
10.2X9.8
能简便的简便不能简便的列出来用托式计算

答案

1.25X0.32=5/4*0.4*0.8=0.5*0.8=0.4
0.56X2.5=0.14*4*2.5=0.14*10=1.4
14.28÷0.7X2.56=2.04*7/0.7*2.56=20.4*2.56=20*2.56+0.4*2.56=51.2+1.24=52.44
1.57X6.4+3.6X1.57=1.57*(6.4+3.6)=1.57*10=15.7
10÷0.1X9.05-26=10*10*9.05-26=905-26=879
10.2X9.8=(10+0.2)*(10-0.2)=10^2-0.2^2=100-0.04=99.96