Question

One estimate of the world population toward the middle of 2009 was 6,774,451,418 people. Round this value to the nearest million. The nearest billion.

Short answer

Answer: The world population, rounded to the nearest million, is 6,800,000,000 and when rounded to the nearest billion, it is 7,000,000,000.

Step-by-step solution

Identifying the million and billion places

Identify the digits in the million and billion places. In the number 6,774,451,418, the million place is occupied by the digit 4 (in 774) and the billion place is occupied by the digit 6.

Rounding to the nearest million

Look at the digit to the right of the million place. If the digit is 5 or greater, round up. If the digit is less than 5, round down. The digit to the right of the million place is 7. Since it is greater than 5, round up by adding 1 to 4. So, the world population, rounded to the nearest million, is 6,800,000,000.

Rounding to the nearest billion

Look at the digit to the right of the billion place. If the digit is 5 or greater, round up. If the digit is less than 5, round down. The digit to the right of the billion place is 7. Since it is greater than 5, round up by adding 1 to 6. So, the world population, rounded to the nearest billion, is 7,000,000,000.