题目内容
脱式计算,能简便计算的要简便计算.
|
(51-
|
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|
|
分析:算式①可将式中分数除法转化成乘法后据减法性质进行计算;
算式②可据乘法分配律进行计算;
算式③运用加法的结合律及交换律进行计算即可;
算式④⑤根据四则混合运算的运算顺序计算即可.
算式②可据乘法分配律进行计算;
算式③运用加法的结合律及交换律进行计算即可;
算式④⑤根据四则混合运算的运算顺序计算即可.
解答:解:①
-
÷
-
,
=
-
×
-
,
=
-(
+
),
=
-1,
=
;
②(51-
)×
,
=51×
-
×
,
=15-
,
=14
;
③
-
×
+
,
=(
+
)-
,
=1-
,
=
;
④
÷(
-
×
),
=
÷(
-
),
=
÷1,
=
;
⑤
×[(
-
)÷
],
=
×[
×
],
=
×
,
=0.1.
7 |
5 |
11 |
18 |
11 |
6 |
2 |
3 |
=
7 |
5 |
11 |
18 |
6 |
11 |
2 |
3 |
=
7 |
5 |
1 |
3 |
2 |
3 |
=
7 |
5 |
=
2 |
5 |
②(51-
34 |
35 |
5 |
17 |
=51×
5 |
17 |
34 |
35 |
5 |
17 |
=15-
2 |
7 |
=14
5 |
7 |
③
5 |
8 |
2 |
3 |
5 |
6 |
3 |
8 |
=(
5 |
8 |
3 |
8 |
5 |
9 |
=1-
5 |
9 |
=
4 |
9 |
④
4 |
15 |
13 |
9 |
7 |
18 |
8 |
7 |
=
4 |
15 |
13 |
9 |
4 |
9 |
=
4 |
15 |
=
4 |
15 |
⑤
7 |
10 |
2 |
3 |
1 |
2 |
7 |
6 |
=
7 |
10 |
1 |
6 |
6 |
7 |
=
7 |
10 |
1 |
7 |
=0.1.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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