25*125*32=25*4*8*125=100*1000+1000003.8-3.8*（3.8-3.8）=3.8-0=3.8（5/8-1/4）*（8/9除4/3）=3/8*36/27=1/2831*36又4/5 +63.2*831=831*184/5+63.2*831=831*(36.8+63.2)=83100