解题过程
解:采用结合律,
原式=80×250×123×4
=250x4x(123x80)
=1000x9840
=9840000
图
80×250×123×4
=(250×4)×80×123
=1000×80×125-1000×80×2
=1000×10000-160000
=10000000-160000
=9840000
=10*8*25*10*123*4
=(10*10)*(25*4)*(8*123)
=100*100*(8*(125-2))
=10000*(8*125-8*2)
=10000*(1000-16)
=9840000