解:①
![](http://thumb.1010pic.com/pic5/latex/12891.png)
+
![](http://thumb.1010pic.com/pic5/latex/36.png)
+
![](http://thumb.1010pic.com/pic5/latex/6237.png)
+
![](http://thumb.1010pic.com/pic5/latex/14.png)
,
=(
![](http://thumb.1010pic.com/pic5/latex/214904.png)
)+(
![](http://thumb.1010pic.com/pic5/latex/173584.png)
),
=1
![](http://thumb.1010pic.com/pic5/latex/157879.png)
,
=
![](http://thumb.1010pic.com/pic5/latex/43128.png)
;
②12.5×8×4×0.25,
=(12.5×8)×(4×0.25),
=100×1,
=100;
③5-
![](http://thumb.1010pic.com/pic5/latex/2321.png)
÷
![](http://thumb.1010pic.com/pic5/latex/6529.png)
-
![](http://thumb.1010pic.com/pic5/latex/14.png)
,
=5
![](http://thumb.1010pic.com/pic5/latex/520268.png)
,
=5
![](http://thumb.1010pic.com/pic5/latex/520269.png)
,
=5-(
![](http://thumb.1010pic.com/pic5/latex/157870.png)
),
=5-1,
=4;
④4.9×6.4+14×0.36-6.4×3.5,
=(4.9-3.5)×6.4+14×0.36,
=1.4×6.4+1.4×3.6,
=1.4×(6.4+3.6),
=1.4×10,
=14.
分析:①
![](http://thumb.1010pic.com/pic5/latex/12891.png)
+
![](http://thumb.1010pic.com/pic5/latex/36.png)
+
![](http://thumb.1010pic.com/pic5/latex/6237.png)
+
![](http://thumb.1010pic.com/pic5/latex/14.png)
,应用加法交换律和结合律进行简算;
②12.5×8×4×0.25,应用乘法结合律进行简算;
③5-
![](http://thumb.1010pic.com/pic5/latex/2321.png)
÷
![](http://thumb.1010pic.com/pic5/latex/6529.png)
-
![](http://thumb.1010pic.com/pic5/latex/14.png)
,先把除数转化为乘它的倒数,然后根据减法的运算性质进行简算;
④4.9×6.4+14×0.36-6.4×3.5,应用乘法分配律进行简算.
点评:此题考查的目的是理解掌握加法、乘法的运算定律,并且能够灵活运用这些运算定律进行简便计算.