题目内容
(2009?兴国县模拟)脱式计算
46×8-120÷15
(12.5×8-40)÷0.6
÷
+
×
÷[(
+
)×
].
46×8-120÷15
(12.5×8-40)÷0.6
7 |
31 |
5 |
2 |
3 |
5 |
7 |
31 |
1 |
5 |
2 |
3 |
1 |
5 |
1 |
13 |
分析:(1)、(2)、(4)根据四则混合运算的顺序计算;
(3)应用乘法分配律进行简算.
(3)应用乘法分配律进行简算.
解答:解:(1)46×8-120÷15,
=368-8,
=360;
(2)(12.5×8-40)÷0.6,
=(100-40)÷0.6,
=60÷0.6,
=100;
(3)
÷
+
×
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(4)
÷[(
+
)×
],
=
÷[
×
],
=
÷
,
=3.
=368-8,
=360;
(2)(12.5×8-40)÷0.6,
=(100-40)÷0.6,
=60÷0.6,
=100;
(3)
7 |
31 |
5 |
2 |
3 |
5 |
7 |
31 |
=
7 |
31 |
2 |
5 |
3 |
5 |
7 |
31 |
=(
2 |
5 |
3 |
5 |
7 |
31 |
=1×
7 |
31 |
=
7 |
31 |
(4)
1 |
5 |
2 |
3 |
1 |
5 |
1 |
13 |
=
1 |
5 |
13 |
15 |
1 |
13 |
=
1 |
5 |
1 |
15 |
=3.
点评:本题主要考查整数的四则混合运算和分数的四则混合运算的计算方法,注意灵活应用运算定律.
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