题目内容
计算下面各题,怎样简便就怎样计算
(1)(2-0.6)÷
|
(2)(
|
(3)2-
|
(4)(0.6-
|
分析:(1)先算括号内的,括号内的结果用小数表示,把除法改为乘法,1.4与7约分;
(2)先算括号内的,再算括号外的;
(3)先算除法,再算减法,在算减法时,运用加法的性质简算;
(4)把0.6化为分数,两个括号同时计算,再算乘法.
(2)先算括号内的,再算括号外的;
(3)先算除法,再算减法,在算减法时,运用加法的性质简算;
(4)把0.6化为分数,两个括号同时计算,再算乘法.
解答:解:(1)(2-0.6)÷
,
=1.4×
,
=3;
(2)(
+
)×
,
=
×
,
=
;
(3)2-
÷
-
,
=2-
×
-
,
=2-
-
,
=2-(
+
),
=2-2,
=0;
(4)(0.6-
)×(
+
),
=(
-
)×
,
=
×
,
=
.
| 7 |
| 15 |
=1.4×
| 15 |
| 7 |
=3;
(2)(
| 5 |
| 6 |
| 5 |
| 8 |
| 4 |
| 25 |
=
| 35 |
| 24 |
| 4 |
| 25 |
=
| 7 |
| 30 |
(3)2-
| 6 |
| 13 |
| 9 |
| 26 |
| 2 |
| 3 |
=2-
| 6 |
| 13 |
| 26 |
| 9 |
| 2 |
| 3 |
=2-
| 4 |
| 3 |
| 2 |
| 3 |
=2-(
| 4 |
| 3 |
| 2 |
| 3 |
=2-2,
=0;
(4)(0.6-
| 3 |
| 10 |
| 2 |
| 9 |
| 1 |
| 3 |
=(
| 6 |
| 10 |
| 3 |
| 10 |
| 5 |
| 9 |
=
| 3 |
| 10 |
| 5 |
| 9 |
=
| 1 |
| 6 |
点评:解答此题,注意数字之间的联系,灵活转化,简便计算.
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