简便计算 2005×0.375-0.375×1949+3.75×2.4

问题描述:

简便计算
2005×0.375-0.375×1949+3.75×2.4

用计算器算

2005×0.375-0.375×1949+3.75×2.4=2005×0375-1949×0.375+24×0.375=(2005-1949+24)×0.375=80×0.375=80×3/8=30

140.16

2005*-0.375*1949+3.75*2.4=(2005-1949+24)*0.375=80*0.375=30

2005×0.375-0.375×1949+0.375×24 =0.375×(2005-1949+24)=0.375×80=30

原式=0.375X(2005-1949加24)=0.375X32=0.375X4X4X2=9