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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