123×64怎样简便计算,560÷5÷16怎样简便计算还有一道,125×64

问题描述:

123×64怎样简便计算,560÷5÷16怎样简便计算
还有一道,125×64

123×64
=(125-2)×64
=125×64-2×64
=125×8×8-128
=1000×8-128
=8000-128
=7872
560÷5÷16
=(7×8×2×5)÷(5×2×8)
=7

123×64=125*64-2*64
=125*8*8-128
=8000-128
=7872
560÷5÷16
=560÷(5*16)
=560÷80
=7

1、123*64=123*(60+4)=7380+492=7872
2、560/5/16=560/(5*16)=560/80=7