Question

0.125乘以0.25乘以0.5乘以64用简便计算怎么做？399.6乘以9—1998乘以0.8用简便计算怎么做？急！求求你们了

温馨提示：在做的时候千万不要弄错，要把乘以的先算哟！

Answer 1

0.125乘以0.25乘以0.5乘以64
=0.125X0.25X0.5X(8X4X2)
=(0.125X8)X(0.25X4)X(0.5X2)
=1X1X1
=1

399.6乘以9—1998乘以0.8
=399.6X9-1998X(0.1X8)
=(199.8X2)X9-(1998X0.1)X8
=199.8X(2X9)-199.8X8
=199.8X(18-8)
=199.8X10
=1998

Answer 2

0.125乘以0.25乘以0.5乘以64
＝0.125x8x0.25x4x0.5x2
=1x1x1
=1

399.6乘以9—1998乘以0.8
=1998x0.2x9-1998x0.8
=1998x1.8-1998x0.8
=1998x(1.8-0.8)
=1998