题目内容
用你喜欢的方法计算.
(1)444
×0.25
(2)27×3.4+15.4×34-340×81%
(3)155×
+
×3
(4)
+
+
+…+
.
(1)444
| 4 |
| 7 |
(2)27×3.4+15.4×34-340×81%
(3)155×
| 23 |
| 156 |
| 11 |
| 156 |
(4)
| 1 |
| 2008 |
| 2 |
| 2008 |
| 3 |
| 2008 |
| 2007 |
| 2008 |
分析:(1)化带分数为整数加分数的形式,再运用乘法分配律解答,
(2)(3)运用乘法分配律解答,
(4)运用高斯定律解答.
(2)(3)运用乘法分配律解答,
(4)运用高斯定律解答.
解答:解:(1)444
×0.25,
=444×0.25+
×0.25,
=111+
,
=111
;
(2)27×3.4+15.4×34-340×81%,
=3.4×(27+154-81),
=3.4×100,
=340;
(3)155×
+
×3,
=156×
-1×
+
,
=23+
,
=23
;
(4)
+
+
+…+
,
=
+
,
=
+
,
=1003+
,
=1003
.
| 4 |
| 7 |
=444×0.25+
| 4 |
| 7 |
=111+
| 1 |
| 7 |
=111
| 1 |
| 7 |
(2)27×3.4+15.4×34-340×81%,
=3.4×(27+154-81),
=3.4×100,
=340;
(3)155×
| 23 |
| 156 |
| 11 |
| 156 |
=156×
| 23 |
| 156 |
| 23 |
| 156 |
| 33 |
| 156 |
=23+
| 10 |
| 156 |
=23
| 5 |
| 78 |
(4)
| 1 |
| 2008 |
| 2 |
| 2008 |
| 3 |
| 2008 |
| 2007 |
| 2008 |
=
| (1+2007)+(2+2006)+…(1003+1005) |
| 2008 |
| 1004 |
| 2008 |
=
| 2008×1003 |
| 2008 |
| 1 |
| 2 |
=1003+
| 1 |
| 2 |
=1003
| 1 |
| 2 |
点评:(1)正确运用乘法分配律,(2)运用高斯定律解决问题,是本题考查知识点.
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