如何巧算13.5乘以9.9+16.5乘以10.1

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如何巧算13.5乘以9.9+16.5乘以10.1如何巧算13.5乘以9.9+16.5乘以10.1如何巧算13.5乘以9.9+16.5乘以10.1原式=13.5×(10-0.1)+16.5×(10+0.

如何巧算13.5乘以9.9+16.5乘以10.1
如何巧算13.5乘以9.9+16.5乘以10.1

如何巧算13.5乘以9.9+16.5乘以10.1
原式=13.5×(10-0.1)+16.5×(10+0.1)
=13.6×10+16.5×10-13.5×0.1-16.5×0.1
=10×(13.5+16.5)+0.1×(-13.5+16.5)
=10×30-0.1×3=300-3=299.7

13.5*(10-0.1)+16.5*(10+0.1)=135-13.5+165+16.5=300+3=303

=13.5*(10-0.1)+16.5*(10+0.1)
=13.5*10-13.5*0.1+16.5*10+16.5*0.1
=(13.5+16.5)*10+(16.5-13.5)*0.1
=30*10+3*0.1
=300+0.3
=300.3