题目内容
(2011?济源模拟)怎样算简便就怎样算.
8.89×36+8.89×63+8.89
1-1÷2-1÷3-
2007×
216×
×(
-
).
8.89×36+8.89×63+8.89
1-1÷2-1÷3-
| 1 |
| 6 |
2007×
| 2005 |
| 2006 |
216×
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 24 |
分析:①8.89×36+8.89×63+8.89,直接利用乘法分配律进行简算;
②1-1÷2-1÷3-
,根据除法与分数之间的关系,转化为:1-
-
-
,再根据减法的运算性质a-b-c=a-(b+c),进行简算;
③2007×
,把2007分解为(2006+1)×
,再利用乘法分配律简算;
④216×
×(
-
),先计算216×
,再利用乘法分配律进行简算;
②1-1÷2-1÷3-
| 1 |
| 6 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 6 |
③2007×
| 2005 |
| 2006 |
| 2005 |
| 2006 |
④216×
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 24 |
| 1 |
| 3 |
解答:解:①8.89×36+8.89×63+8.89,
=8.89×(36+63+1),
=8.89×100,
=889;
②1-1÷2-1÷3-
,
=1-
-
-
,
=1-(
+
+
),
=1-1,
=0;
③2007×
,
=(2006+1)×
,
=2006×
+
,
=2005+
,
=2005
;
④216×
×(
-
),
=72×(
-
),
=72×
-72×
,
=24-3,
=21.
=8.89×(36+63+1),
=8.89×100,
=889;
②1-1÷2-1÷3-
| 1 |
| 6 |
=1-
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 6 |
=1-(
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 6 |
=1-1,
=0;
③2007×
| 2005 |
| 2006 |
=(2006+1)×
| 2005 |
| 2006 |
=2006×
| 2005 |
| 2006 |
| 2005 |
| 2006 |
=2005+
| 2005 |
| 2006 |
=2005
| 2005 |
| 2006 |
④216×
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 24 |
=72×(
| 1 |
| 3 |
| 1 |
| 24 |
=72×
| 1 |
| 3 |
| 1 |
| 24 |
=24-3,
=21.
点评:此题是考查分数四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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