A community with a population of two million three hundred and ten thousand people living in an area of two…

Analyze the question We need the population density of a community, given its population and the area it occupies.

Concept Population density is the number of individuals per unit area:

Population density = Total population ÷ Area

Solution

• Population = 2,310,000 people
• Area = 2,310 km²

Population density = 2,310,000 ÷ 2,310

Cancel the common factor 2,310:

2,310,000 ÷ 2,310 = 1,000 people per km²

Answer The population density is 1,000 persons per square kilometre.

Tip In density questions, look for a common factor before dividing. Here, 2,310,000 is just 2,310 × 1,000, so the answer comes out in seconds. Always write out the numbers in digits first, because the wording "two million three hundred and ten thousand" can be confusing under exam pressure.