题目内容
计算下面各题,能简便的要简便. 0.35×101 |
43-(
| ||||||
2.125×
|
3÷
| ||||||
0.4×(4.7-3.65) | 12.5×2.6×0.8. |
分析:(1)把101看作100+1,运用乘法分配律简算;
(2)先算括号内的除法,把
化为小数,运用减法的性质简算;
(3)把除法改为乘法,运用乘法分配律简算;
(4)先算除法,再算减法;
(5)先算括号内的,再算括号外的;
(6)运用乘法交换律与结合律简算.
(2)先算括号内的除法,把
3 |
5 |
(3)把除法改为乘法,运用乘法分配律简算;
(4)先算除法,再算减法;
(5)先算括号内的,再算括号外的;
(6)运用乘法交换律与结合律简算.
解答:解:(1)0.35×101,
=0.35×(100+1),
=35+0.35,
=35.35;
(2)43-(
+24÷
),
=43-(0.6+24×
),
=43-(0.6+9),
=43-9-0.6,
=33.4;
(3)2.125×
+1.875÷4,
=2.125×
+1.875×
,
=(2.125+1.875)×
,
=4×
,
=1;
(4)3÷
-
÷3,
=3×4-
×
,
=12-
,
=11
;
(5)0.4×(4.7-3.65),
=0.4×1.05,
=0.42;
(6)12.5×2.6×0.8,
=(12.5×0.8)×2.6,
=10×2.6,
=26.
=0.35×(100+1),
=35+0.35,
=35.35;
(2)43-(
3 |
5 |
8 |
3 |
=43-(0.6+24×
3 |
8 |
=43-(0.6+9),
=43-9-0.6,
=33.4;
(3)2.125×
1 |
4 |
=2.125×
1 |
4 |
1 |
4 |
=(2.125+1.875)×
1 |
4 |
=4×
1 |
4 |
=1;
(4)3÷
1 |
4 |
1 |
4 |
=3×4-
1 |
4 |
1 |
3 |
=12-
1 |
12 |
=11
11 |
12 |
(5)0.4×(4.7-3.65),
=0.4×1.05,
=0.42;
(6)12.5×2.6×0.8,
=(12.5×0.8)×2.6,
=10×2.6,
=26.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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