0.5x12.5x6.4x2.5
=0.5x12.5x(8x0.8)x2.5
=(12.5x8)x(0.5x0.8x2.5)
=100x(0.4x2.5)
=100x1
=100
方法:
拆分利用乘法结合律实现简便计算。
100
12.5x0.64x2.5 =(12.5x0.8)x(0.4x2.5x2) =10x2 =20
解,原式=0.5x12.5x(8x0.4x2)x2.5
=(0.5x2)x(12.5x8)x(0.4x2.5)
=1x100x1
=100
0.5x12.5x6.4x2.5
=0.5x12.5x0.8x8x2.5
=0.5x10x20
=100
------------
0.5x12.5x6.4x2.5
=0.5x12.5x2.5x0.8x4x2
=0.5x2 x 12.5x0.8 x2.5x4
=1x10x10
=100