AMC 8 2024 Problem 2

AMC8 2024 年第 2 题

表达式与运算★☆☆☆☆
What is the value of this expression in decimal form? 4411+11044+441100\displaystyle \frac{44}{11} + \frac{110}{44} + \frac{44}{1100}
请问下列表达式的值用小数可以表示为哪一项?
  1. A.6.4
  2. B.6.504
  3. C.6.54
  4. D.6.9
  5. E.6.94

正确答案 · Correct Answer

C

解析 · Solution

解法1

我们看到4411\displaystyle \frac{44}{11}等于4;11044\displaystyle \frac{110}{44}化简为52\displaystyle \frac{5}{2},即2.5;而441100\displaystyle \frac{44}{1100}化简为125\displaystyle \frac{1}{25},即0.04;4+2.5+0.04得出$ $4411\displaystyle \frac{44}{11}$ + $11044\displaystyle \frac{110}{44}$ + $441100\displaystyle \frac{44}{1100}$ $是(C)6.54。使用直接计算,我们可以将4411\displaystyle \frac{44}{11}化为44001100\displaystyle \frac{4400}{1100},11044\displaystyle \frac{110}{44}化为27501100\displaystyle \frac{2750}{1100},再加上441100\displaystyle \frac{44}{1100},然后相加得到71941100\displaystyle \frac{7194}{1100},化简后即为(C)6.54。

Solution 1

We see that 4411\displaystyle \frac{44}{11} is 4; 11044\displaystyle \frac{110}{44} simplifies to 52\displaystyle \frac{5}{2}, which is 2.5; and 441100\displaystyle \frac{44}{1100} simplifies to 125\displaystyle \frac{1}{25}, which is 0.04; 4+2.5+0.04 reveals
4411+11044+441100\frac{44}{11} + \frac{110}{44} + \frac{44}{1100}
is (C) 6.54. Using brute force we can make 4411\displaystyle \frac{44}{11} into 44001100\displaystyle \frac{4400}{1100}, 11044\displaystyle \frac{110}{44} into 27501100\displaystyle \frac{2750}{1100}, and 441100\displaystyle \frac{44}{1100}, and then we add and get 71941100\displaystyle \frac{7194}{1100} and this simplifies to (C) 6.54.

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