原式=3.78╳10.1-37.83.78Ⅹ10.1-3.78X10=3.78(10.1-10)=3.78╳0.1=0.378
巧算过程如下所示
3.78×10.1-37.8
=3.78×(10+0.1)-37.8
=3.78×10+3.78×0.1-37.8
=37.8+3.78×0.1-37.8
=3.78×0.1
=0.378
3.78x10.1-37.8=3.78x(10+0.1)-37.8=3.78x0.1=0.378
37.8=3.78*10
3.78*10.1-3.78*10
=3.78*(10.1-10)
=3.78*0.1=0.378
3.78*10.1-37.8
=3.78*(10+0.1)-37.8
=3.78*10+3.78*0.1-37.8
=37.8-37.8+0.378
=0.378