用简便方法计算,4.8*125,5*2.5*12.5*64,6.5*12.8-6.5*2.8
问题描述:
用简便方法计算,4.8*125,5*2.5*12.5*64,6.5*12.8-6.5*2.8
答
4.8*125=0.6*(8*125)=0.6*1000=600,
5*2.5*12.5*64=(5*2)*(2.5*4)*(12.5*8)=10*10*100=10000,
6.5*12.8-6.5*2.8=6.5*(12.8-2.8)=6.5*10=65.