六年级数学题，急急急急~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

计算，能简算的要简算。
125×4×0.8×2.5
=(125x0.8)x(4x2.5)
=100x10
=1000

15分之11×8分之3＋8分之3×15分之4
=3/8x(11/15+4/15)
=3/8x1
=3/8

(0.25＋0.25×99)×6
=0.25x(1+99)x6
=0.25x100x6
=25x6
=150

125×4×0.8×2.5
=(125×0.8)×(4×2.5)
=100×10
=1000

15分之11×8分之3＋8分之3×15分之4
=(15分之11＋15分之4)×8分之3
=8分之3

(0.25＋0.25×99)×6
=(0.25×1＋0.25×99)×6
=(1+99))×0.25×6
=100×6
=600

你要会凑，比如看到2.5，你就要想到4，把他们都凑成整数，好算的数，知道不？这样省时间。

125×4×0.8×2.5
=(125x0.8)x(4x2.5)
=100x10
=1000

15分之11×8分之3＋8分之3×15分之4
=3/8x(11/15+4/15)
=3/8x1
=3/8

(0.25＋0.25×99)×6
=0.25x(1+99)x6
=0.25x100x6
=25x6
=150

125×4×0.8×2.5
=(125x0.8)x(4x2.5)
=100x10
=1000

15分之11×8分之3＋8分之3×15分之4
=3/8x(11/15+4/15)
=3/8x1
=3/8

(0.25＋0.25×99)×6
=0.25x(1+99)x6
=0.25x100x6
=25x6