题目内容
神机妙算细又巧:
(54+
|
36÷[(
|
2-
| ||||||||||||||||
[
|
|
(
|
分析:(1)根据乘法分配律进行计算;
(2)根据乘法分配律进行计算;
(3)先算除法,再根据连减的性质进行计算;
(4)根据连减的性质进行计算中括号里面的,最后算除法;
(5)根据乘法分配律进行计算;
(6)根据乘法分配律进行计算.
(2)根据乘法分配律进行计算;
(3)先算除法,再根据连减的性质进行计算;
(4)根据连减的性质进行计算中括号里面的,最后算除法;
(5)根据乘法分配律进行计算;
(6)根据乘法分配律进行计算.
解答:解:(1)(54+
)÷9,
=(54+
)×
,
=54×
+
×
,
=6+
,
=6
;
(2)36÷[(
-
)×3],
=36÷[(
×3-
×3],
=36÷[2.5-1],
=36÷1.5,
=24;
(3)2-
÷
-
,
=2-
-
,
=2-(
+
),
=2-2,
=0;
(4)[
-(
-
)]÷4,
=[
-
+
]÷4,
=[
+
-
]÷4,
=[1-
]÷4,
=
÷4,
=
;
(5)
÷5+
÷2,
=
×
+
×
,
=
×(
+
),
=
×
,
=
;
(6)(
+
)×8+
,
=
×8+
×8+
,
=5+
+
,
=5+(
+
),
=5+1,
=6.
9 |
13 |
=(54+
9 |
13 |
1 |
9 |
=54×
1 |
9 |
9 |
13 |
1 |
9 |
=6+
1 |
13 |
=6
1 |
13 |
(2)36÷[(
5 |
6 |
1 |
3 |
=36÷[(
5 |
6 |
1 |
3 |
=36÷[2.5-1],
=36÷1.5,
=24;
(3)2-
6 |
13 |
9 |
26 |
2 |
3 |
=2-
4 |
3 |
2 |
3 |
=2-(
4 |
3 |
2 |
3 |
=2-2,
=0;
(4)[
3 |
5 |
3 |
4 |
2 |
5 |
=[
3 |
5 |
3 |
4 |
2 |
5 |
=[
3 |
5 |
2 |
5 |
3 |
4 |
=[1-
3 |
4 |
=
1 |
4 |
=
1 |
16 |
(5)
7 |
8 |
7 |
8 |
=
7 |
8 |
1 |
5 |
7 |
8 |
1 |
2 |
=
7 |
8 |
1 |
5 |
1 |
2 |
=
7 |
8 |
7 |
10 |
=
49 |
80 |
(6)(
5 |
8 |
1 |
27 |
19 |
27 |
=
5 |
8 |
1 |
27 |
19 |
27 |
=5+
8 |
27 |
19 |
27 |
=5+(
8 |
27 |
19 |
27 |
=5+1,
=6.
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.
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