Population DensityPopulation DensityExploring the relationship

between population and land area

Population in 2005Population in 2005

The population of the world by the The population of the world by the end of 2005 will be approximately end of 2005 will be approximately 6,464,750,000 people.6,464,750,000 people.

The population density of the world The population density of the world in 2005 is 48 people per square in 2005 is 48 people per square kilometer. kilometer.

Population in 2050Population in 2050

How old will you be in 2050? How old will you be in 2050? Do you think you will haveDo you think you will have

children of your own in 2050?children of your own in 2050?

The projected population of the world The projected population of the world in 2050 is 9,075,903,000.in 2050 is 9,075,903,000.

The projected population density is The projected population density is 67 people per square kilometer.67 people per square kilometer.

Population in TheoryPopulation in Theory

If each of these boxes represent 1 square If each of these boxes represent 1 square kilometer and each black dot represents a kilometer and each black dot represents a person, this is what the world’s population person, this is what the world’s population density would look like in 2005 and 2050.density would look like in 2005 and 2050.

2005 2050

Population in RealityPopulation in Reality

In reality, the population density much more dense in In reality, the population density much more dense in some places than others. Urban areas are more dense some places than others. Urban areas are more dense than rural areas, and some countries are more dense than rural areas, and some countries are more dense than others.than others.

2005 2050

PurposePurpose This exercise helps students compare the This exercise helps students compare the

relative population density of different relative population density of different countries and examine its effects.countries and examine its effects.

The WorldThe World The total population of the world is:The total population of the world is:

Approximately 6,326,005,560 peopleApproximately 6,326,005,560 people

The total land area of the world is: The total land area of the world is: Approximately 510,072,000 sq kmApproximately 510,072,000 sq km

World PopulationWorld Population

The three most populous countries The three most populous countries are:are:

1.1. China - 1,273,111,290 people China - 1,273,111,290 people 2.2. India - 1,029,991,145 peopleIndia - 1,029,991,145 people3.3. United States - 278,058,881 peopleUnited States - 278,058,881 people

Their land areas are:Their land areas are:1.1. China - 9,326,410 sq kmChina - 9,326,410 sq km2.2. India – 2,973,190 sq kmIndia – 2,973,190 sq km3.3. United States - 9,158,960 sq kmUnited States - 9,158,960 sq km

Let’s Round the NumbersLet’s Round the Numbers

Take these numbers and round them Take these numbers and round them to the nearest hundred million.to the nearest hundred million.

China - 1,273,111,290China - 1,273,111,290

Hundred million place

United States - United States - 278,058,881278,058,881

≈ 1,300,000,000

India - 1,029,991,145India - 1,029,991,145

Hundred million place

≈ 1,000,000,000

Hundred million place

≈ 300,000,000

More Rounding!More Rounding!

Then round these numbers to the Then round these numbers to the nearest million.nearest million.

China - 9,326,410 sq kmChina - 9,326,410 sq km

United States - 9,158,960 sq kmUnited States - 9,158,960 sq km

Millions place

Millions place

Millions place

≈ 9,000,000 sq km

≈ 9,000,000 sq km

≈ 3,000,000 sq kmIndia – 2,973,190 sq kmIndia – 2,973,190 sq km

Land Resources in China Land Resources in China and the U.S.and the U.S.

Take your rounded numbers for the Take your rounded numbers for the areas of China and the United States areas of China and the United States and find the ratio of land area and find the ratio of land area between China and the United between China and the United States.States.

Do the figures you calculated seem Do the figures you calculated seem to match the relative sizes of the to match the relative sizes of the countries on the two maps?countries on the two maps?

Population in China and the U.S.Population in China and the U.S.

What is the ratio What is the ratio of people in of people in China to people China to people in the United in the United States?States?

Population in China and the U.S.Population in China and the U.S. Take the candies and separate them Take the candies and separate them

into groups representing the ratio of into groups representing the ratio of people in China and the U.S.people in China and the U.S.

It is easy to do this by taking the ratio and count It is easy to do this by taking the ratio and count that number for each pile until they are all gone.that number for each pile until they are all gone.

For example:For example: If the ratio was 2:1, you would put If the ratio was 2:1, you would put 2 in the first pile and then 1 in the second pile 2 in the first pile and then 1 in the second pile over and over until they are all gone.over and over until they are all gone.

How many people per candy?How many people per candy? Now count the number of candies that Now count the number of candies that

you have in the China pile. How many you have in the China pile. How many people are represented by each candy?people are represented by each candy?

Example if you have 50 candies in the China pile and Example if you have 50 candies in the China pile and there are 1,300,000,000 people in China then:there are 1,300,000,000 people in China then:

1,300,000,00050

2

-10 300

6,000,000

Now you can do the same with the United States Now you can do the same with the United States numbers!numbers!

This means with 50 candies each candy represents 26,000,000 people.

-300 0

Putting It All TogetherPutting It All Together

Now take the candies that are for China Now take the candies that are for China and put them inside the lines on your and put them inside the lines on your map.map.

Then take the United States candies and Then take the United States candies and put them inside the lines of your United put them inside the lines of your United States map.States map.

DiscussionDiscussion

Which country has more space per Which country has more space per person? person?

How do you think this would change How do you think this would change a person’s experience living in that a person’s experience living in that country?country?

Look at a population map of China Look at a population map of China and the United States. Is the and the United States. Is the population spread out evenly? Why population spread out evenly? Why or why not?or why not?

Maps

China

United States