题目内容
| 计算下列各题(能简便要使用简便方法) 30×(
|
[1-(
| ||||||||||||
5÷
|
|
分析:(1)30×(
+
),运用乘法分配律进行简算;
(2)[1-(
+
)]×
,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计算;
(3)5÷
+
÷5,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计算;
(4)
÷
+
×
,首先把除数转化为乘它的倒数,再运用乘法分配律进行简算.
| 3 |
| 5 |
| 1 |
| 6 |
(2)[1-(
| 3 |
| 4 |
| 1 |
| 12 |
| 3 |
| 2 |
(3)5÷
| 5 |
| 6 |
| 5 |
| 6 |
(4)
| 7 |
| 9 |
| 11 |
| 5 |
| 2 |
| 9 |
| 5 |
| 11 |
解答:解:(1)30×(
+
),
=30×
+30×
,
=18+5,
=23;
(2)[1-(
+
)]×
,
=[1-
]×
,
=
×
,
=
;
(3)5÷
+
÷5,
=5×
+
×
,
=6+
,
=6
;
(4)
÷
+
×
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
.
| 3 |
| 5 |
| 1 |
| 6 |
=30×
| 3 |
| 5 |
| 1 |
| 6 |
=18+5,
=23;
(2)[1-(
| 3 |
| 4 |
| 1 |
| 12 |
| 3 |
| 2 |
=[1-
| 5 |
| 6 |
| 3 |
| 2 |
=
| 1 |
| 6 |
| 3 |
| 2 |
=
| 1 |
| 4 |
(3)5÷
| 5 |
| 6 |
| 5 |
| 6 |
=5×
| 6 |
| 5 |
| 5 |
| 6 |
| 1 |
| 5 |
=6+
| 1 |
| 6 |
=6
| 1 |
| 6 |
(4)
| 7 |
| 9 |
| 11 |
| 5 |
| 2 |
| 9 |
| 5 |
| 11 |
=
| 7 |
| 9 |
| 5 |
| 11 |
| 2 |
| 9 |
| 5 |
| 11 |
=(
| 7 |
| 9 |
| 2 |
| 9 |
| 5 |
| 11 |
=1×
| 5 |
| 11 |
=
| 5 |
| 11 |
点评:此题考查的目的是掌握分数四则混合运算的顺序和计算法则,并且能够灵活运用运算定律进行简便计算.
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