题目内容
(2012?安徽模拟)怎样算简便就怎样算:
÷[(
-
)×
];
15.28-3.99-9.01;
×
-
÷4.
| 6 |
| 7 |
| 4 |
| 7 |
| 1 |
| 2 |
| 2 |
| 5 |
15.28-3.99-9.01;
| 14 |
| 15 |
| 1 |
| 4 |
| 2 |
| 15 |
分析:算式(1)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
算式(2)可根据一个数连续减两个数等于减去这两个数的和的减法性质进行简便计算;
算式(3)可根据乘法分配律进行简便计算.
算式(2)可根据一个数连续减两个数等于减去这两个数的和的减法性质进行简便计算;
算式(3)可根据乘法分配律进行简便计算.
解答:解:(1)
÷[(
-
)×
],
=
÷[
×
],
=
÷
,
=
×35,
=25;
(2)15.28-3.99-9.01,
=15.28-(3.99+9.01),
=15.28-13,
=2.28;
(3)
×
-
÷4,
=
×
-
×
,
=(
-
)×
,
=
×
,
=
.
| 6 |
| 7 |
| 4 |
| 7 |
| 1 |
| 2 |
| 2 |
| 5 |
=
| 6 |
| 7 |
| 1 |
| 14 |
| 2 |
| 5 |
=
| 5 |
| 7 |
| 1 |
| 35 |
=
| 5 |
| 7 |
=25;
(2)15.28-3.99-9.01,
=15.28-(3.99+9.01),
=15.28-13,
=2.28;
(3)
| 14 |
| 15 |
| 1 |
| 4 |
| 2 |
| 15 |
=
| 14 |
| 15 |
| 1 |
| 4 |
| 2 |
| 15 |
| 1 |
| 4 |
=(
| 14 |
| 15 |
| 2 |
| 15 |
| 1 |
| 4 |
=
| 4 |
| 5 |
| 1 |
| 4 |
=
| 1 |
| 5 |
点评:完成此类题意要注意分析式中数据的特点及内在联系,根据数据的特点及内在联系选择合适的简便方法计算.
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