题目内容
(2010?临澧县)
| 脱式计算,能简算的要简算. 79×
|
| ||||||||
4×[(
|
14÷
|
分析:(1)79×
,转化为:(78+1)×
,运用乘法分配律进行简算;
(2)
÷
÷
,把除数转化为乘它的倒数,再进行计算;
(3)4×[(
+
)÷6],根据分数四则混合运算的顺序,按照分数四则运算的计算法则进行简算;
(4)14÷
+295×86.把除数转化为乘它的倒数,再运用乘法分配律进行简算.
| 9 |
| 78 |
| 9 |
| 78 |
(2)
| 5 |
| 8 |
| 20 |
| 21 |
| 7 |
| 12 |
(3)4×[(
| 5 |
| 6 |
| 2 |
| 3 |
(4)14÷
| 1 |
| 295 |
解答:解:(1)79×
,
=(78+1)×
,
=78×
+1×
,
=9+
,
=9
;
(2)
÷
÷
,
=
×
×
,
=1
;
(3)4×[(
+
)÷6],
=4×[
×
],
=4×
,
=1;
(4)14÷
+295×86.
=14×295+295×86,
=(14+86)×295,
=100×295,
=29500.
| 9 |
| 78 |
=(78+1)×
| 9 |
| 78 |
=78×
| 9 |
| 78 |
| 9 |
| 78 |
=9+
| 9 |
| 78 |
=9
| 9 |
| 78 |
(2)
| 5 |
| 8 |
| 20 |
| 21 |
| 7 |
| 12 |
=
| 5 |
| 8 |
| 21 |
| 20 |
| 12 |
| 7 |
=1
| 1 |
| 8 |
(3)4×[(
| 5 |
| 6 |
| 2 |
| 3 |
=4×[
| 9 |
| 6 |
| 1 |
| 6 |
=4×
| 1 |
| 4 |
=1;
(4)14÷
| 1 |
| 295 |
=14×295+295×86,
=(14+86)×295,
=100×295,
=29500.
点评:此题主要考查分数四则混合运算,注意运算顺序和计算法则,能够灵活选择简便方法进行简算.
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