题目内容
(2010?海安县)计算下面各题,能简便计算的要简便计算
+
÷
73÷
-37×
1÷(15-
-
)
÷[(
+
)×
].
| 5 |
| 8 |
| 3 |
| 8 |
| 2 |
| 3 |
73÷
| 3 |
| 7 |
| 7 |
| 3 |
1÷(15-
| 12 |
| 5 |
| 13 |
| 5 |
| 3 |
| 5 |
| 7 |
| 9 |
| 1 |
| 3 |
| 3 |
| 2 |
分析:算式(1)(4)根据四则混合运算的运算顺序进行计算即可:先算乘除,再算加减,有括号的要先算括号里面的.
算式(2)可根据乘法分配律进行简便计算;
算式(3)中括号内的减法算式可以根据一个数减两个数等于减去这两个数的和减法性质进行计算;
算式(2)可根据乘法分配律进行简便计算;
算式(3)中括号内的减法算式可以根据一个数减两个数等于减去这两个数的和减法性质进行计算;
解答:解:(1)
+
÷
=
+
×
,
=
+
,
=
;
(2)73÷
-37×
=73×
-37×
,
=(73-37)×
,
=36×
,
=84;
(3)1÷(15-
-
)
=1÷[15-(
+
],
=1÷(15-5),
=1÷10,
=
;
(4)
÷[(
+
)×
].
=
÷[(
+
)×
],
=
÷(
×
),
=
÷
,
=
×
,
=
.
| 5 |
| 8 |
| 3 |
| 8 |
| 2 |
| 3 |
=
| 5 |
| 8 |
| 3 |
| 8 |
| 3 |
| 2 |
=
| 10 |
| 16 |
| 9 |
| 16 |
=
| 19 |
| 16 |
(2)73÷
| 3 |
| 7 |
| 7 |
| 3 |
=73×
| 7 |
| 3 |
| 7 |
| 3 |
=(73-37)×
| 7 |
| 3 |
=36×
| 7 |
| 3 |
=84;
(3)1÷(15-
| 12 |
| 5 |
| 13 |
| 5 |
=1÷[15-(
| 12 |
| 5 |
| 13 |
| 5 |
=1÷(15-5),
=1÷10,
=
| 1 |
| 10 |
(4)
| 3 |
| 5 |
| 7 |
| 9 |
| 1 |
| 3 |
| 3 |
| 2 |
=
| 3 |
| 5 |
| 7 |
| 9 |
| 3 |
| 9 |
| 3 |
| 2 |
=
| 3 |
| 5 |
| 10 |
| 9 |
| 3 |
| 2 |
=
| 3 |
| 5 |
| 5 |
| 3 |
=
| 3 |
| 5 |
| 3 |
| 5 |
=
| 9 |
| 25 |
点评:完成本题时要注意分析式中数据的特点及内在联系,然后选择合适的方法进行计算.
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