题目内容
灵活计算.
(0.75-
|
(
| ||||||||||||||
1÷
|
201×
|
分析:(1)把小数化为分数,先算括号内的,再算乘法;
(2)运用减法的性质以及加法交换律与结合律简算;
(3)把除法改为乘法,约分计算;
(4)把201看作(200+1),运用乘法分配律简算.
(2)运用减法的性质以及加法交换律与结合律简算;
(3)把除法改为乘法,约分计算;
(4)把201看作(200+1),运用乘法分配律简算.
解答:解:(1)(0.75-
)×(
+
),
=(
-
)×
,
=
×
,
=
;
(2)(
-
)-(
-
),
=
-
-
+
,
=(
+
)-(
+
),
=1-
,
=
;
(3)1÷
÷
÷
÷…÷
,
=1×
×
×
×…×
,
=
;
(4)201×
,
=(200+1)×
,
=200×
+1×
,
=199+
,
=199
.
| 3 |
| 16 |
| 2 |
| 9 |
| 1 |
| 3 |
=(
| 3 |
| 4 |
| 3 |
| 16 |
| 5 |
| 9 |
=
| 9 |
| 16 |
| 5 |
| 9 |
=
| 5 |
| 16 |
(2)(
| 5 |
| 8 |
| 1 |
| 6 |
| 2 |
| 3 |
| 3 |
| 8 |
=
| 5 |
| 8 |
| 1 |
| 6 |
| 2 |
| 3 |
| 3 |
| 8 |
=(
| 5 |
| 8 |
| 3 |
| 8 |
| 1 |
| 6 |
| 2 |
| 3 |
=1-
| 5 |
| 6 |
=
| 1 |
| 6 |
(3)1÷
| 3 |
| 2 |
| 4 |
| 3 |
| 5 |
| 4 |
| 51 |
| 50 |
=1×
| 2 |
| 3 |
| 3 |
| 4 |
| 4 |
| 5 |
| 50 |
| 51 |
=
| 2 |
| 51 |
(4)201×
| 199 |
| 200 |
=(200+1)×
| 199 |
| 200 |
=200×
| 199 |
| 200 |
| 199 |
| 200 |
=199+
| 199 |
| 200 |
=199
| 199 |
| 200 |
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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