题目内容
脱式计算,能用简便方法要用简算.
2001×
|
349×101-349 | 37×9.25+37×
| ||||||
306×35-4080÷24 | 9
|
6.8×16.8+19.3×3.2. |
分析:(1)先把2001分解成2002-1,再运用乘法分配律简算;
(2)(3)运用乘法分配律简算;
(4)同时运算乘法和除法,再算减法;
(5)根据减法的性质简算;
(6)同时运算两个乘法,再算加法.
(2)(3)运用乘法分配律简算;
(4)同时运算乘法和除法,再算减法;
(5)根据减法的性质简算;
(6)同时运算两个乘法,再算加法.
解答:解:(1)2001×
,
=(2002-1)×
,
=2002×
-1×
,
=2001-
,
=2000
;
(2)349×101-349,
=349×(101-1),
=349×100,
=34900;
(3)37×9.25+37×
,
=37×(9.25+
),
=37×10,
=370;
(4)306×35-4080÷24,
=10710-170,
=10540;
(5)9
-6
-1
,
=9
-(6
+1
),
=9
-8,
=1
;
(6)6.8×16.8+19.3×3.2,
=114.24+61.76,
=176.
2001 |
2002 |
=(2002-1)×
2001 |
2002 |
=2002×
2001 |
2002 |
2001 |
2002 |
=2001-
2001 |
2002 |
=2000
1 |
2002 |
(2)349×101-349,
=349×(101-1),
=349×100,
=34900;
(3)37×9.25+37×
3 |
4 |
=37×(9.25+
3 |
4 |
=37×10,
=370;
(4)306×35-4080÷24,
=10710-170,
=10540;
(5)9
5 |
12 |
13 |
27 |
14 |
27 |
=9
5 |
12 |
13 |
27 |
14 |
27 |
=9
5 |
12 |
=1
5 |
12 |
(6)6.8×16.8+19.3×3.2,
=114.24+61.76,
=176.
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.
练习册系列答案
相关题目
脱式计算,能用简便方法要用简算.
2001× | 349×101-349 | 37×9.25+37× |
306×35-4080÷24 | 9-6-1 | 6.8×16.8+19.3×3.2. |