题目内容
神机妙算细又巧!(写出简算过程)
2004×
(
+
)×15×17
÷
+
÷
-
-
+
.
2004×
| 2002 |
| 2003 |
(
| 1 |
| 15 |
| 2 |
| 17 |
| 1 |
| 3 |
| 5 |
| 8 |
| 2 |
| 3 |
| 5 |
| 8 |
| 11 |
| 10 |
| 1 |
| 4 |
| 3 |
| 4 |
| 9 |
| 10 |
分析:(1)2004×
,把2004看成2003+1,根据乘法分配律展开,然后进行约分即可;
(2)(
+
)×15×17,根据乘法分配律进行计算即可;
(3)
÷
+
÷
,根据乘法分配律进行计算即可;
(4)
-
-
+
,分别减去
、
,就是减去这两个数的和,然后再进行计算即可.
| 2002 |
| 2003 |
(2)(
| 1 |
| 15 |
| 2 |
| 17 |
(3)
| 1 |
| 3 |
| 5 |
| 8 |
| 2 |
| 3 |
| 5 |
| 8 |
(4)
| 11 |
| 10 |
| 1 |
| 4 |
| 3 |
| 4 |
| 9 |
| 10 |
| 1 |
| 4 |
| 3 |
| 4 |
解答:解:
(1)2004×
,
=
,
=
,
=
,
=2002+
,
=2002
;
(2)(
+
)×15×17,
=
×15×17+
×15×17,
=17+30,
=47;
(3)
÷
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(4)
-
-
+
,
=(
+
)-(
+
),
=2-1,
=1.
(1)2004×
| 2002 |
| 2003 |
=
| 2004×2002 |
| 2003 |
=
| (2003+1)×2002 |
| 2003 |
=
| 2003×2002+2002 |
| 2003 |
=2002+
| 2002 |
| 2003 |
=2002
| 2002 |
| 2003 |
(2)(
| 1 |
| 15 |
| 2 |
| 17 |
=
| 1 |
| 15 |
| 2 |
| 17 |
=17+30,
=47;
(3)
| 1 |
| 3 |
| 5 |
| 8 |
| 2 |
| 3 |
| 5 |
| 8 |
=
| 1 |
| 3 |
| 8 |
| 5 |
| 2 |
| 3 |
| 8 |
| 5 |
=(
| 1 |
| 3 |
| 2 |
| 3 |
| 8 |
| 5 |
=1×
| 8 |
| 5 |
=
| 8 |
| 5 |
(4)
| 11 |
| 10 |
| 1 |
| 4 |
| 3 |
| 4 |
| 9 |
| 10 |
=(
| 11 |
| 10 |
| 9 |
| 10 |
| 1 |
| 4 |
| 3 |
| 4 |
=2-1,
=1.
点评:根据所学的运算定律,结合给出的数据,选择合适的运算定律进行简便计算即可.
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