1989 AMC 8 第 4 题

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所有题目均经美国数学协会(MAA)官方合法授权使用。

4.

下列哪个数最接近

4010.205\frac{401}{0.205}\text{。}

Estimate to determine which of the following is closest to

4010.205.\frac{401}{0.205}.

0.20.2

22

2020

200200

20002000

答案:E
知识点:估算
难度评级:660
小提示:

4014010.2050.205 都估成容易计算的数

Round 401401 and 0.2050.205 to simple numbers

大提示:

4010.2054000.2\frac{401}{0.205} \approx \frac{400}{0.2}

解答:

把分子和分母分别取成便于计算的近似数,得到 4010.2054000.2\frac{401}{0.205} \approx \frac{400}{0.2}

由于 4000.2=2000\frac{400}{0.2} = 2000,原数最接近 20002000

所以正确答案是 E

Round the numerator and denominator: 4010.2054000.2.\frac{401}{0.205} \approx \frac{400}{0.2}.

Since 4000.2=2000,\frac{400}{0.2} = 2000, the value is closest to 2000.2000.

Thus, the correct answer is E .

第 3 题#3
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