题目内容
怎样简便怎样算
(1)
÷8+
×
(2)
×5÷
×5
(3)
×[
-(
-
)]
(4)[2-(1
-1.5)÷1
]×6
.
(1)
| 7 |
| 18 |
| 1 |
| 8 |
| 11 |
| 18 |
(2)
| 2 |
| 3 |
| 2 |
| 3 |
(3)
| 5 |
| 18 |
| 3 |
| 4 |
| 11 |
| 20 |
| 1 |
| 4 |
(4)[2-(1
| 2 |
| 3 |
| 5 |
| 12 |
| 3 |
| 8 |
考点:分数的四则混合运算
专题:运算顺序及法则
分析:(1)利用乘法分配律即可:
(2)先算除法再算乘法即可;
(3)把小括号去掉在计算较为简便;
(4)把小括号里的小数化成分数计算后再算除法,减法和乘法.
(2)先算除法再算乘法即可;
(3)把小括号去掉在计算较为简便;
(4)把小括号里的小数化成分数计算后再算除法,减法和乘法.
解答:
解:(1)
÷8+
×
=
×
+
×
=
×(
+
)
=
×1
=
(2)
×5÷
×5
=5×(
÷
)×5
=5×5
=25
(3)
×[
-(
-
)]
=
×[
+
-
]
=
×[1-
]
=
×
=
(4)[2-(1
-1.5)÷1
]×6
=[2-(
-
)×
]×
=[2-
×
]×
=[2-
]×
=
×
=12
| 7 |
| 18 |
| 1 |
| 8 |
| 11 |
| 18 |
=
| 7 |
| 18 |
| 1 |
| 8 |
| 1 |
| 8 |
| 11 |
| 18 |
=
| 1 |
| 8 |
| 7 |
| 18 |
| 11 |
| 18 |
=
| 1 |
| 8 |
=
| 1 |
| 8 |
(2)
| 2 |
| 3 |
| 2 |
| 3 |
=5×(
| 2 |
| 3 |
| 2 |
| 3 |
=5×5
=25
(3)
| 5 |
| 18 |
| 3 |
| 4 |
| 11 |
| 20 |
| 1 |
| 4 |
=
| 5 |
| 18 |
| 3 |
| 4 |
| 1 |
| 4 |
| 11 |
| 20 |
=
| 5 |
| 18 |
| 11 |
| 20 |
=
| 5 |
| 18 |
| 9 |
| 20 |
=
| 1 |
| 8 |
(4)[2-(1
| 2 |
| 3 |
| 5 |
| 12 |
| 3 |
| 8 |
=[2-(
| 5 |
| 3 |
| 3 |
| 2 |
| 12 |
| 17 |
| 51 |
| 8 |
=[2-
| 1 |
| 6 |
| 12 |
| 17 |
| 51 |
| 8 |
=[2-
| 2 |
| 17 |
| 51 |
| 8 |
=
| 32 |
| 17 |
| 51 |
| 8 |
=12
点评:此题主要考查分数、整数、小数的四则混合运算的运算顺序和应用运算定律进行简便计算.
练习册系列答案
相关题目
一个电话号码是7位数,逆时针旋转90度,再旋转90度,是9160619.原电话号码是( )
| A、9160619 |
| B、6190916 |
| C、9190919 |
| D、6160616 |