题目内容
你想怎么算就怎么算.
|
| (
| ||||||||||||||||||||
(
| 12×(
|
|
考点:分数的四则混合运算,分数的简便计算
专题:运算顺序及法则,运算定律及简算
分析:(1)把除法化成乘法,再运用乘法的分配律进行简算;
(2)先分别求出乘除法算式的结果,再算减法;
(3)运用乘法的分配律进行简算;
(4)先运用乘法的分配律进行简算,再运用加法的结合律进行简算;
(5)运用乘法的分配律进行简算;
(6)先算小括号里的加法,再算中括号里的乘法,最后算括号外的除法.
(2)先分别求出乘除法算式的结果,再算减法;
(3)运用乘法的分配律进行简算;
(4)先运用乘法的分配律进行简算,再运用加法的结合律进行简算;
(5)运用乘法的分配律进行简算;
(6)先算小括号里的加法,再算中括号里的乘法,最后算括号外的除法.
解答:
解:(1)
×
+
÷31
=
×
+
×
=(
+
)×
=1×
=
;
(2)
÷
-
×
=
-
=
;
(3)(
+
-
)×12
=
×12+
×12-
×12
=4+3-2
=7-2
=5;
(4)(
+
)×8+
=
×8+
×8+
=3+
+
=3+(
+
)
=3+1
=4;
(5)12×(
-
)×11
=12×
×11-12×
×11
=48-11
=37;
(6)
÷[(
+
)×
]
=
÷[
×
]
=
÷
=
.
| 7 |
| 41 |
| 1 |
| 31 |
| 34 |
| 41 |
=
| 7 |
| 41 |
| 1 |
| 31 |
| 34 |
| 41 |
| 1 |
| 31 |
=(
| 7 |
| 41 |
| 34 |
| 41 |
| 1 |
| 31 |
=1×
| 1 |
| 31 |
=
| 1 |
| 31 |
(2)
| 1 |
| 6 |
| 11 |
| 24 |
| 3 |
| 8 |
| 4 |
| 11 |
=
| 4 |
| 11 |
| 3 |
| 22 |
=
| 5 |
| 22 |
(3)(
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 6 |
=
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 6 |
=4+3-2
=7-2
=5;
(4)(
| 3 |
| 8 |
| 1 |
| 27 |
| 19 |
| 27 |
=
| 3 |
| 8 |
| 1 |
| 27 |
| 19 |
| 27 |
=3+
| 8 |
| 27 |
| 19 |
| 27 |
=3+(
| 8 |
| 27 |
| 19 |
| 27 |
=3+1
=4;
(5)12×(
| 4 |
| 11 |
| 1 |
| 12 |
=12×
| 4 |
| 11 |
| 1 |
| 12 |
=48-11
=37;
(6)
| 1 |
| 5 |
| 1 |
| 12 |
| 1 |
| 6 |
| 1 |
| 3 |
=
| 1 |
| 5 |
| 1 |
| 4 |
| 1 |
| 3 |
=
| 1 |
| 5 |
| 1 |
| 12 |
=
| 12 |
| 5 |
点评:四则运算,先弄清运算顺序,然后再进一步计算即可,能简算的要简算.
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