题目内容
用你喜欢的方法算:可要仔细哟!!
(1)
×
+
÷
(2)
-
÷
+
(3)
÷(
+
×
)
(4)(9×
-4)÷
(5)[(4+
)÷
]×
(6)
÷[
+(1-
)].
(1)
4 |
3 |
2 |
7 |
5 |
7 |
3 |
4 |
(2)
1 |
2 |
4 |
25 |
2 |
5 |
1 |
4 |
(3)
1 |
4 |
5 |
8 |
3 |
8 |
8 |
5 |
(4)(9×
2 |
3 |
4 |
5 |
(5)[(4+
3 |
2 |
2 |
5 |
5 |
12 |
(6)
3 |
11 |
2 |
5 |
10 |
11 |
分析:(1)变形后可以运用乘法分配律简算;其余各题按照先算乘除,再算加减,有括号的先算括号里面的运算顺序计算.
解答:解:(1)
×
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(2)
-
÷
+
,
=
-
+
,
=
+
,
=
;
(3)
÷(
+
×
),
=
÷(
+
),
=
÷
,
=
;
(4)(9×
-4)÷
,
=(6-4)÷
,
=2÷
,
=
;
(5)[(4+
)÷
]×
,
=[
÷
]×
,
=
×
,
=
;
(6)
÷[
+(1-
)],
=
÷[
+
],
=
÷
,
=
.
4 |
3 |
2 |
7 |
5 |
7 |
3 |
4 |
=
4 |
3 |
2 |
7 |
5 |
7 |
4 |
3 |
=(
2 |
7 |
5 |
7 |
4 |
3 |
=1×
4 |
3 |
=
4 |
3 |
(2)
1 |
2 |
4 |
25 |
2 |
5 |
1 |
4 |
=
1 |
2 |
2 |
5 |
1 |
4 |
=
1 |
10 |
1 |
4 |
=
7 |
20 |
(3)
1 |
4 |
5 |
8 |
3 |
8 |
8 |
5 |
=
1 |
4 |
5 |
8 |
3 |
5 |
=
1 |
4 |
49 |
40 |
=
10 |
49 |
(4)(9×
2 |
3 |
4 |
5 |
=(6-4)÷
4 |
5 |
=2÷
4 |
5 |
=
5 |
2 |
(5)[(4+
3 |
2 |
2 |
5 |
5 |
12 |
=[
11 |
2 |
2 |
5 |
5 |
12 |
=
55 |
4 |
5 |
12 |
=
275 |
48 |
(6)
3 |
11 |
2 |
5 |
10 |
11 |
=
3 |
11 |
2 |
5 |
1 |
11 |
=
3 |
11 |
27 |
55 |
=
5 |
9 |
点评:乘法分配律是常用的简便运算的方法,要熟练掌握,灵活运用.
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