用一下交换律和结合律
427-165+173-35
=(427+173)-(165+35)
=600-200=400
简算如下,上式=427+173-(165+35)=600+200=800
427-165+173一35
=(427+173)-(165+35)
=500一200
=300
427-165+173-35简便方法?
427-165+173-35
=(427+173)-(165+35)
=600-200
=400
427-165+173-35=(427+173)-(165+35)=600-200=400