题目内容
计算下面各题,能简便计算的要简便计算.
|
| (2-
| ||||||||||||||||||||
18×(
|
|
|
考点:分数的四则混合运算,运算定律与简便运算
专题:运算顺序及法则,运算定律及简算
分析:(1)按照从左向右的顺序进行计算;
(2)根据乘法分配律进行简算;
(3)先算小括号里面的除法,再算减法,最后算括号外面的除法;
(4)根据乘法分配律进行简算;
(5)先算减法,再算乘法,最后算除法;
(6)先算加法,再算乘法,最后算除法.
(2)根据乘法分配律进行简算;
(3)先算小括号里面的除法,再算减法,最后算括号外面的除法;
(4)根据乘法分配律进行简算;
(5)先算减法,再算乘法,最后算除法;
(6)先算加法,再算乘法,最后算除法.
解答:
解:(1)
÷
×
=4×
=
;
(2)
÷9-
×
=
×
-
×
=(
-
)×
=1×
=
;
(3)(2-
÷
)÷
=(2-
)÷
=
÷
=18;
(4)18×(
+
-
)
=18×
+18×
-18×
=12+27-10
=39-10
=29;
(5)
÷[(
-
)×14]
=
÷[
×14]
=
÷7
=
;
(6)
÷[(
+
)×
]
=
÷[
×
]
=
÷
=
.
| 6 |
| 7 |
| 3 |
| 14 |
| 5 |
| 6 |
=4×
| 5 |
| 6 |
=
| 10 |
| 3 |
(2)
| 7 |
| 5 |
| 2 |
| 5 |
| 1 |
| 9 |
=
| 7 |
| 5 |
| 1 |
| 9 |
| 2 |
| 5 |
| 1 |
| 9 |
=(
| 7 |
| 5 |
| 2 |
| 5 |
| 1 |
| 9 |
=1×
| 1 |
| 9 |
=
| 1 |
| 9 |
(3)(2-
| 1 |
| 2 |
| 3 |
| 4 |
| 2 |
| 9 |
=(2-
| 2 |
| 3 |
| 2 |
| 9 |
=
| 4 |
| 3 |
| 2 |
| 9 |
=18;
(4)18×(
| 2 |
| 3 |
| 3 |
| 2 |
| 5 |
| 9 |
=18×
| 2 |
| 3 |
| 3 |
| 2 |
| 5 |
| 9 |
=12+27-10
=39-10
=29;
(5)
| 7 |
| 12 |
| 11 |
| 6 |
| 4 |
| 3 |
=
| 7 |
| 12 |
| 1 |
| 2 |
=
| 7 |
| 12 |
=
| 1 |
| 12 |
(6)
| 4 |
| 25 |
| 2 |
| 5 |
| 1 |
| 3 |
| 9 |
| 11 |
=
| 4 |
| 25 |
| 11 |
| 15 |
| 9 |
| 11 |
=
| 4 |
| 25 |
| 3 |
| 5 |
=
| 4 |
| 15 |
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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