题目内容
| 脱式计算: 48-[32÷(
|
1
| ||||||||||
|
2-(1-25%)÷30%÷3. |
考点:分数的四则混合运算
专题:运算顺序及法则
分析:(1)先算小括号内的,再算中括号内的,最后算括号外的.
(2)先算括号内的除法,再算括号内的加法,最后算括号外的乘法.
(3)先算括号内的,再算括号外的除法和乘法.
(4)把百分数化为分数,先算括号内的,再算括号外的除法,最后算减法.
(2)先算括号内的除法,再算括号内的加法,最后算括号外的乘法.
(3)先算括号内的,再算括号外的除法和乘法.
(4)把百分数化为分数,先算括号内的,再算括号外的除法,最后算减法.
解答:
解:(1)48-[32÷(
+
)]
=48-[32÷1]
=48-32
=16
(2)1
×(14÷
+
)
=
×(14×
+
)
=
×(16+
)
=
×
=
(3)
÷(
÷
)×
=
÷(
×
)×
=
÷
×
=
×
×
=
(4)2-(1-25%)÷30%÷3
=2-
÷
÷3
=2-
×
×
=2-
=
| 3 |
| 5 |
| 2 |
| 5 |
=48-[32÷1]
=48-32
=16
(2)1
| 1 |
| 8 |
| 7 |
| 8 |
| 2 |
| 3 |
=
| 9 |
| 8 |
| 8 |
| 7 |
| 2 |
| 3 |
=
| 9 |
| 8 |
| 2 |
| 3 |
=
| 9 |
| 8 |
| 50 |
| 3 |
=
| 75 |
| 4 |
(3)
| 3 |
| 4 |
| 15 |
| 16 |
| 5 |
| 6 |
| 7 |
| 8 |
=
| 3 |
| 4 |
| 15 |
| 16 |
| 6 |
| 5 |
| 7 |
| 8 |
=
| 3 |
| 4 |
| 9 |
| 8 |
| 7 |
| 8 |
=
| 3 |
| 4 |
| 8 |
| 9 |
| 7 |
| 8 |
=
| 7 |
| 12 |
(4)2-(1-25%)÷30%÷3
=2-
| 3 |
| 4 |
| 3 |
| 10 |
=2-
| 3 |
| 4 |
| 10 |
| 3 |
| 1 |
| 3 |
=2-
| 5 |
| 6 |
=
| 7 |
| 6 |
点评:此题考查了分数的四则混合运算,注意运算顺序和运算法则.
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