题目内容
脱式计算.
(1)7.8÷[32×(1-
)+3.6
(2)[5-3
+(1
+2.25×
)]÷0.125.
(1)7.8÷[32×(1-
| 5 |
| 8 |
(2)[5-3
| 7 |
| 6 |
| 5 |
| 6 |
| 1 |
| 3 |
分析:(1)先算小括号里的减法,再算中括号里的乘法,再算中括号里的加法,最后算括号外的除法,
(2)根据四则混合运算的顺序计算即可:先算乘除,再算加减,有括号先算括号里面的.
(2)根据四则混合运算的顺序计算即可:先算乘除,再算加减,有括号先算括号里面的.
解答:解:(1)7.8÷[32×(1-
)+3.6],
=7.8÷[32×
+3.6],
=7.8÷[12+3.6],
=7.8÷15.6,
=0.5;
(2)[5-3
+(1
+2.25×
)]÷0.125,
=[5-3
+(1
+0.75)]÷0.125,
=[5-3
+
]÷0.125,
=[
+
]÷0.125,
=
÷0.125,
=
.
| 5 |
| 8 |
=7.8÷[32×
| 3 |
| 8 |
=7.8÷[12+3.6],
=7.8÷15.6,
=0.5;
(2)[5-3
| 7 |
| 6 |
| 5 |
| 6 |
| 1 |
| 3 |
=[5-3
| 7 |
| 6 |
| 5 |
| 6 |
=[5-3
| 7 |
| 6 |
| 13 |
| 12 |
=[
| 5 |
| 6 |
| 13 |
| 12 |
=
| 23 |
| 12 |
=
| 46 |
| 3 |
点评:考查了整数、小数、分数四则混合运算的顺序,注意有括号的运算方法.
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