题目内容
| 计算,能简算的要简算. 75×
|
13.7-1.4+0.6 |
| ||||||||||||
2012×
|
66-195÷3+1498 | (
|
分析:(1)先把除法变成乘法,再运用乘法分配律简算;
(2)按照从左到右的顺序计算;
(3)先算小括号里面的减法,再算括号外的乘法,最后算加法;
(4)先把2012分解2011+1,再运用乘法分配律简算;
(5)先算除法,再算减法,最后算加法;
(6)运用乘法分配律简算.
(2)按照从左到右的顺序计算;
(3)先算小括号里面的减法,再算括号外的乘法,最后算加法;
(4)先把2012分解2011+1,再运用乘法分配律简算;
(5)先算除法,再算减法,最后算加法;
(6)运用乘法分配律简算.
解答:解:(1)75×
+25÷
,
=75×
+25×
,
=(75+25)×
,
=100×
,
=60;
(2)13.7-1.4+0.6,
=12.3+0.6,
=12.9;
(3)
+
×(
-
),
=
+
×2,
=
+
,
=
;
(4)2012×
,
=(2011+1)×
,
=2011×
+1×
,
=2010+
,
=2010
;
(5)66-195÷3+1498,
=66-65+1498,
=1+1498,
=1499;
(6)(
+
)×40,
=
×40+
×40,
=25+28,
=53.
| 3 |
| 5 |
| 5 |
| 3 |
=75×
| 3 |
| 5 |
| 3 |
| 5 |
=(75+25)×
| 3 |
| 5 |
=100×
| 3 |
| 5 |
=60;
(2)13.7-1.4+0.6,
=12.3+0.6,
=12.9;
(3)
| 1 |
| 12 |
| 11 |
| 12 |
| 5 |
| 2 |
| 1 |
| 2 |
=
| 1 |
| 12 |
| 11 |
| 12 |
=
| 1 |
| 12 |
| 22 |
| 12 |
=
| 23 |
| 12 |
(4)2012×
| 2010 |
| 2011 |
=(2011+1)×
| 2010 |
| 2011 |
=2011×
| 2010 |
| 2011 |
| 2010 |
| 2011 |
=2010+
| 2010 |
| 2011 |
=2010
| 2010 |
| 2011 |
(5)66-195÷3+1498,
=66-65+1498,
=1+1498,
=1499;
(6)(
| 5 |
| 8 |
| 7 |
| 10 |
=
| 5 |
| 8 |
| 7 |
| 10 |
=25+28,
=53.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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