题目内容
用简便方法计算
|
|
77×
|
考点:分数的简便计算
专题:运算定律及简算
分析:①除以
,等于乘
,然后根据乘法交换律;
②除以3等于乘
,然后根据乘法分配律,提取
,进而得解.
③把77写成(76+1),然后根据乘法分配律计算.
| 4 |
| 5 |
| 5 |
| 4 |
②除以3等于乘
| 1 |
| 3 |
| 1 |
| 3 |
③把77写成(76+1),然后根据乘法分配律计算.
解答:
解:①
×8÷
=
×
×8
=2;
②
×
+
÷3
=
×
+
×
=
×(
+
)
=
×
=
;
③77×
=(76+1)×
=76×
+1×
=3+
=3
.
| 1 |
| 5 |
| 4 |
| 5 |
=
| 1 |
| 5 |
| 5 |
| 4 |
=2;
②
| 1 |
| 3 |
| 5 |
| 12 |
| 1 |
| 4 |
=
| 1 |
| 3 |
| 5 |
| 12 |
| 1 |
| 4 |
| 1 |
| 3 |
=
| 1 |
| 3 |
| 5 |
| 12 |
| 3 |
| 12 |
=
| 1 |
| 3 |
| 2 |
| 3 |
=
| 2 |
| 9 |
③77×
| 3 |
| 76 |
=(76+1)×
| 3 |
| 76 |
=76×
| 3 |
| 76 |
| 3 |
| 76 |
=3+
| 3 |
| 76 |
=3
| 3 |
| 76 |
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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