(2014•广州模拟)计算下列各题,能简便的请用简便方法
1个回答

解题思路:(1)根据乘法分配律进行简算;

(2)根据乘法分配律进行简算;

(3)根据乘法结合律进行简算;

(4)根据乘法分配律进行简算.

(1)

4

7×23

12

13+

4

1

13+16×

1

7

=

4

7×(23

12

13+

1

13)+4×4×

1

7

=

4

7×24+4×

4

7

=

4

7×(24+4)

=

4

7×28

=16;

(2)41.2×3.6+16×1

1

4+53.7×6.4

=41.2×3.6+20+53.7×6.4

=41.2×(10-6.4)+20+53.7×6.4

=41.2×10-41.2×6.4+20+53.7×6.4

=412+20+53.7×6.4-41.2×6.4

=432+(53.7-41.2)×6.4

=432+12.5×8×0.8

=432+80

=512;

(3)0.78÷2.6×1.8÷0.12

=(0.78÷2.6)×(1.8÷0.12)

=0.3×15

=4.5;

(4)12.6×125%+3

2

4

5

=12.6×1.25+3

2

5×1.25

=(12.6+3

2

5)×1.25

=16×1.25

=1×(8×1.25)

=20.

点评:

本题考点: 运算定律与简便运算.

考点点评: 完成本题要注意分析式中数据,运用合适的简便方法计算.