题目内容
能用简便算法用简便方法计算.
|
64×(
| ||||||||||||
18.75×
|
|
考点:运算定律与简便运算,整数、分数、小数、百分数四则混合运算
专题:运算顺序及法则,运算定律及简算
分析:①
=37.5%,根据乘法分配律,提取
;
②根据除法分配律的逆运算,展开,首先计算乘然后求和差;
③
=62.5%,根据乘法分配律,提取
,然后求差;
④
÷
=
×
,
÷7=
×
,
=37.5%,根据乘法分配律,提取
,即可得解.
| 3 |
| 8 |
| 3 |
| 8 |
②根据除法分配律的逆运算,展开,首先计算乘然后求和差;
③
| 5 |
| 8 |
| 5 |
| 8 |
④
| 2 |
| 7 |
| 8 |
| 3 |
| 2 |
| 7 |
| 3 |
| 8 |
| 3 |
| 8 |
| 3 |
| 8 |
| 1 |
| 7 |
| 3 |
| 8 |
| 3 |
| 8 |
解答:
解:①
×325+37.5%×475
=
×(325+475)
=
×800
=300
②64×(
+
-
)
=64×
+64×
-64×
=48+4-24
=28
③18.75×
-7.75×
-62.5%
=
×(18.75-7.75-1)
=
×10
=6.25
④
÷
+
×37.5%+
÷7
=
×
+
×
+
×
=
×(
+
+
)
=
×1
=
| 3 |
| 8 |
=
| 3 |
| 8 |
=
| 3 |
| 8 |
=300
②64×(
| 3 |
| 4 |
| 1 |
| 16 |
| 3 |
| 8 |
=64×
| 3 |
| 4 |
| 1 |
| 16 |
| 3 |
| 8 |
=48+4-24
=28
③18.75×
| 5 |
| 8 |
| 5 |
| 8 |
=
| 5 |
| 8 |
=
| 5 |
| 8 |
=6.25
④
| 2 |
| 7 |
| 8 |
| 3 |
| 4 |
| 7 |
| 3 |
| 8 |
=
| 2 |
| 7 |
| 3 |
| 8 |
| 4 |
| 7 |
| 3 |
| 8 |
| 3 |
| 8 |
| 1 |
| 7 |
=
| 3 |
| 8 |
| 2 |
| 7 |
| 4 |
| 7 |
| 1 |
| 7 |
=
| 3 |
| 8 |
=
| 3 |
| 8 |
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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