题目内容
(1)[9
-(8-
)]÷2×
;
(2)
.
| 2008 |
| 2009 |
| 1 |
| 2009 |
| 1 |
| 2 |
(2)
4.75×
| ||||
| 8.68-0.36+4.32-1.64 |
分析:(1)把9
拆成9+
,中括号内运用减法的性质以及加法交换律与结合律简算;
(2)把4.75化成假分数,与
约分;分母部分运用加法交换律与结合率简算.
| 2008 |
| 2009 |
| 2008 |
| 2009 |
(2)把4.75化成假分数,与
| 8 |
| 19 |
解答:解:(1)[9
-(8-
)]÷2×
,
=[9+
-8+
)]÷2×
,
=[(9-8)+(
+
)]÷2×
,
=[1+1]÷2×
,
=2÷2×
,
=1×
,
=
;
(2)
,
=
,
=
,
=
,
=
.
| 2008 |
| 2009 |
| 1 |
| 2009 |
| 1 |
| 2 |
=[9+
| 2008 |
| 2009 |
| 1 |
| 2009 |
| 1 |
| 2 |
=[(9-8)+(
| 2008 |
| 2009 |
| 1 |
| 2009 |
| 1 |
| 2 |
=[1+1]÷2×
| 1 |
| 2 |
=2÷2×
| 1 |
| 2 |
=1×
| 1 |
| 2 |
=
| 1 |
| 2 |
(2)
4.75×
| ||||
| 8.68-0.36+4.32-1.64 |
=
| ||||||||
| (8.68+4.32)-(0.36+1.64) |
=
2+
| ||
| 13-2 |
=
| ||
| 11 |
=
| 272 |
| 165 |
点评:仔细观察算式特点,灵活运用运算定律或运算技巧,进行简算.
练习册系列答案
相关题目