2.8乘2.5乘1.25乘4用简便算

问题描述:

2.8乘2.5乘1.25乘4用简便算

2.8x2.5x1.25x4
=(0.7x4)x2.5x1.25x4
=0.7x(4x2.5)x(1.25x4)
=0.7x10x5
=35

0.7x4x2.5x1.25x4=35

2.8乘2.5乘1.25乘4
=0.7x(4x2.5)x(1.25x4)
=0.7x10x5
=35