四升五年级数学 简便计算常见类型举例

四升五年级数学 简便计算常见类型举例


简介:
3.29+0.73+2.27(加法结合律) =3.29+(0.73+2.27) =3.29+3 =6.29 7.325-(5.325+1.7)(减法性质) =7.325-5.325-1.7 =2-1.7 =0.3 3.29×0.25×4(乘法结合律) =3.29×(0.25×4) =3.29×1 =3.29 0.25×0.28(乘法结合律) =0.25×(0.4×0.7) =(0.25×0.4)×0.7 =0.1×0.7 =0.07