题目内容
| 下面各题,怎样简便就怎样算. | |
| ( | 12×( |
解:(1)
×
×18=3;
(2)
+
÷
+
,
=
+
×
+
,
=
+
+
,
=
+(
+
),
=
+1,
=1
;
(3)(
+
+
)×24,
=
×24+
×24+
×24,
=12+16+18,
=46;
(4)12×(
-
),
=12×
-12×
,
=9-2,
=7;
(5)
÷
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(6)
×
+
÷
,
=
+
×
,
=
+2,
=2
.
分析:(1)约分计算;
(2)把除法改为乘法,运用加法结合律简算;
(3)(4)运用乘法分配律简算;
(5)把除法改为乘法,运用乘法分配律简算;
(6)把除法改为乘法,约分计算.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
(2)
=
=
=
=
=1
(3)(
=
=12+16+18,
=46;
(4)12×(
=12×
=9-2,
=7;
(5)
=
=(
=1×
=
(6)
=
=
=2
分析:(1)约分计算;
(2)把除法改为乘法,运用加法结合律简算;
(3)(4)运用乘法分配律简算;
(5)把除法改为乘法,运用乘法分配律简算;
(6)把除法改为乘法,约分计算.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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