57.56-7.81-2.19的简便计算是:
57.56-(7.81+2.19)
=57.56-10
=47.56
57.56-7.81-2.19
=57.56-(7.81+2.19)
=57.56-10
=47.56
使用的是减法的性质
57.56-7.81-2.19=57.56-(7.81+2.19)=57.56-10=47.56。
简便计算方法是:
57.56-7.81-2.19
=57.56-(7.81+2.19)
=57.56-10
=47.56
这道题目需要用小括号来计算,如下:
57.56-7.81-2.19
=57.56-(7.81+2.19)
=57.56-10
=47.56