能巧算的要巧算:2.5*1.9+25*0.71+0.25 *1.0

问题描述:

能巧算的要巧算:2.5*1.9+25*0.71+0.25 *1.0

2.5*1.9+25*0.71+0.25 *1.0 =25*0.19+25*0.71+0.25=25*(0.19+0.71)+0.25=25*0.9+0.25=25-2.5+0.25=22.75