“[17.1减17.1除以（3.1减1.2）]乘0.6”的简便算法

(17.1-17.1/(3.1-1.2))×0.6
=((3.1-1.2-1)/(3.1-1.2))×17.1×0.6
=((2.1-1.2)/(3.1-1.2))×17.1×0.6
=((2-1+0.1-0.2)/(3-1+0.1-0.2))×17.1×0.6
=((1-0.1)/(2-0.1))×17.1×0.6
=(0.9/1.9)×17.1×0.6
=(171×6×9)/(19×100)
=(9×6×9)/100
=486/100
=4.86

[17.1-17.1/(3.1-1.2)]*0.6
=(0.9*9)*0.6
=13.5

[17.1-17.1/（3.1-1.2）]*0.6
=[17.1-(19-1.9)/1.9]*0.6
=(17.1-19/1.9+1.9/1.9)*0.6
=(17.1-10+1)*0.6
=(17.1-9)*0.6
=8.1*0.6
=4.86