五年级上册数学小数乘法简便运算专练

五年级上册数学小数乘法简便运算专练


简介:
1、乘法交换律和结合律 1.78×2.5×4 1.25×4.3×0.8 =1.78 ×(2.5×4) =(1.25×0.8)×4.3 =1.78×10 =1×4.3 =17.8 =4.3 0.25×4.78×4 =(0.25×4)×4.78 =1×4.78 =4.78 1.25×32×0.25 7.5×16 =7.5×8+7.5×8 =60+60 =120