56×1.25=?3.4×7×1.5=?0.8×0.25×0.4×12.5=?递等式计算、要简便哦!有奖金!_数学解答

56×1.25=?3.4×7×1.5=?0.8×0.25×0.4×12.5=?递等式计算、要简便哦!有奖金!

人气：447 ℃　时间：2019-08-09 22:24:03

解答

56×1.25
=7x8x1.25
=7x10
=70
3.4×7×1.5
=1.7x7x1.5x2
=11.9x3
=35.7
0.8×0.25×0.4×12.5
=(0.8×12.5)×(0.4×0.25)
=10x0.1
=1