在算式中:只含加减或乘除时要从左往右计算。

算式中含有两级的时候要先算乘除法、后算加减法。

算式中有括号的时候先算括号里面的，后算括号外面的。

一、脱式计算

125xx41x25-220-x4

460÷

63+84x2÷42

二、简便计算下面各题96+266+20472x125

782x101-782

28x2+28x70+28x2857

:7090÷7+24x5x125x64x186-86x5xx38+38xx526

x6-110x13xx163x99800-5÷2050

分数、百分数脱式计算练习48

310

1、7/25×4/9+7/25×5/9

=7/25×(4/9+5/9)

=7/25×1

=7/25

2、60×(1/12+1/15+1/4)

=60×1/12+60×1/15+60×1/4

=5+4+15

=24

3、(5/12-3/8)×72

=5/12×72-3/8×72

=30-27

=3

4、6/7-5/24÷7/12

=6/7-5/24×12/7

=12/14-5/14

=7/14

=1/2

5、[3/4×(7/16-1/4)]÷9/13

=3/4×（7/16-4/16）×13/9

=1/4×3/16×13/3

=13/64

6、2/3-7/8+1/3

=(2/3+1/3)-7/8

=1-7/8

=1/8

7、5/6-(3/7-1/6)

=(5/6+1/6)-3/7

=1-3/7

=4/7

8、1-1/3-2/3

=1-(1/3+2/3)

=1-1

=0

9、1+3/5-1/10

=1+6/10-1/10

=1+1/2

=1又1/2

10、3/8-12/13+5/8

=3/8+5/8-12/13

=1-12/13

=1/13