Look at the table below. Which of the following has NOT been rounded correctly to the nearest hundred?
| City | Exact Population | Estimated Population |
|---|---|---|
| Austin | 690,252 | 690,300 |
| Chicago | 3,844,829 | 3,844,800 |
| Seattle | 557,087 | 557,100 |
| St. Louis | 912,332 | 912,330 |
A. Chicago
B. Austin
C. Seattle
D. St. Louis
Answer (1)
Analyze each city's population and rounding:
Austin: 690,252 rounds to 690,300 (Correct).
Chicago: 3,844,829 rounds to 3,844,800 (Correct).
Seattle: 557,087 rounds to 557,100 (Correct).
St. Louis: 912,332 rounds to 912,300, but the table shows 912,330 (Incorrect).
St. Louis is not rounded correctly, so the answer is D .
Explanation
Problem Analysis We are given a table with the exact and estimated populations of four cities. Our task is to identify which city's estimated population is NOT correctly rounded to the nearest hundred. To do this, we will examine each city individually and compare its exact population to its estimated population.
Austin's Population For Austin, the exact population is 690,252. To round to the nearest hundred, we look at the tens digit, which is 5. Since the tens digit is 5 or greater, we round up. Therefore, 690,252 rounded to the nearest hundred is 690,300. The table shows 690,300, which is correct.
Chicago's Population For Chicago, the exact population is 3,844,829. To round to the nearest hundred, we look at the tens digit, which is 2. Since the tens digit is less than 5, we round down. Therefore, 3,844,829 rounded to the nearest hundred is 3,844,800. The table shows 3,844,800, which is correct.
Seattle's Population For Seattle, the exact population is 557,087. To round to the nearest hundred, we look at the tens digit, which is 8. Since the tens digit is 5 or greater, we round up. Therefore, 557,087 rounded to the nearest hundred is 557,100. The table shows 557,100, which is correct.
St. Louis's Population For St. Louis, the exact population is 912,332. To round to the nearest hundred, we look at the tens digit, which is 3. Since the tens digit is less than 5, we round down. Therefore, 912,332 rounded to the nearest hundred is 912,300. The table shows 912,330, which is incorrect.
Conclusion Therefore, St. Louis's population has not been rounded correctly to the nearest hundred.
Final Answer The answer is D.
Examples
Rounding to the nearest hundred is a useful skill in everyday life. For example, if you are estimating the cost of groceries, you might round each item to the nearest hundred to get a quick estimate of the total cost. This can help you stay within your budget. Another example is when estimating the number of people at an event. If you count 234 people, you might round this to 200 to give a general idea of the crowd size. Rounding makes numbers easier to work with and understand in many situations.
