Lesson video

Hello, my name is Mrs. Grey, and I'm so excited that you've decided to learn geography with me today.

Today's lesson is in our unit of Population, Where Do People Live? And the title of the lesson is Population Structure.

By the end of the lesson, you will be able to interpret and analyse population pyramids.

There are some keywords that we'll come across in today's lesson.

They are population pyramid, birth rate, and life expectancy.

Now, population pyramid is a graphical representation of age and sex distribution in a population.

Birth rate is the number of live births per thousand people per year.

And life expectancy is the average number of years a person may expect to live.

Our lesson is split into two cycles.

The first, what are the features of a population pyramid, and the second, what does a population pyramid shape tell us? So let's first look at the features of a population pyramid.

So this is a population pyramid.

It's a type of graph that shows the age and sex distribution of a population.

So you can see it's two bar graphs side by side, using the same scale in the middle, and then a scale along the bottom.

Male is on one side and female is on the other side.

The Y axis shows the age group, so that axis up the middle that is shared between two of the bar charts shows the age group.

The top of the pyramid shows the elderly, so the oldest people in the population.

The base of the pyramid shows young children.

You can see the bottom scale there, the bottom of the Y axis is naught to four year olds.

This shows young children.

Now, the X axis along the bottom, this shows the population in percentage, so you can see, at the bottom, it goes from 0% right in the middle to 10% right along the edge.

So the middle of the pyramid shows 0%, and then the length of the bar, that shows the number or the percentage of people within each age group.

So let's check what we've learned so far.

So which part of the population pyramid shows age groups? Is it the Y axis, the X axis, or the title? So pause the video, write down your answer, and then come back and let's see how you got on.

Okay, so which part of the population pyramid shows age groups? The answer is Y axis.

Well done.

The axis that goes up the middle.

Well done.

Okay, so let's have a little look at this pyramid then.

The left-hand side of the pyramid, that shows the males that are in the population.

So for each of the different age groups, it shows the males that are in the population.

The right-hand side of the pyramid, that shows the females in the population, so again, for each of the different age categories, that shows the percentage of females in the population.

So the left side shows the males and the right side shows the females.

So let's do a little check then true or false, the left side of a population pyramid shows the females in a population.

Is that true or false? Pause the video, write down your answer, and then come back and let's see how you got on.

Okay, how did you get on? So true or false, the left side of a population pyramid shows the females in a population? And that's false.

But why? The left side of the pyramid shows the males in a population and the right hand side shows the females.

Well done.

So in this particular pyramid, 9% of the population are males age naught to four.

So have a little look at that left-hand side.

Have a look at the Y axis where it says naught to four, and you can see the length of that bar falls right in between 8% and 10%, so that's 9%.

So 9% of the population are males age naught to four.

Now, 4% of the population are females aged 25 to 29.

So if you have a look at the Y axis along the middle again, you go to 25 to 29, you have a look at the right-hand side, which is the female side, and see how long that bar goes, and you go down to the X axis at the bottom, you can see that that's 4%.

And this is how you read a population pyramid.

So for each of the different age groups, each of the age groups has got a bar, and you just need to see where along the X axis that bar comes to, and that's the proportion of the population in that particular age group.

So which age group has the highest proportion of the population? How would we answer that question? Which age group has the highest proportion of the population? So we've got all the different age groups along the middle.

What we need to do is look at which bars are the longest, so which part are the longest, and therefore have the highest proportion of the population? So Sam says it's naught to four years because it's got the longest bars, and that's right.

Well done, Sam.

So naught to four has got the longest bars in both and female, so that is the age group with the highest proportion of the population.

So what percentage of the population are males aged 45 to 49? So how are we gonna answer that one, the percentage of the population that are males aged 45 to 49? So we need to find the side of the population pyramid that's males, so that's the left-hand side.

We look at the Y axis and we find the 45 to 49 age group.

And then we look at how far along that bar comes along the X axis.

And the answer is two, Jun says that the answer is 2%, and that's correct.

Well done.

Okay, so now we've come to our first practise task of the lesson.

So we've got a few different questions here to answer based on this population pyramid.

So let's have a look at these questions then.

Question one, which axis of a population pyramid shows age groups? Question two, which axis of a population pyramid shows population? So have a look at that image that's there, the population pyramid, and have a look at which axis shows age groups and which axis shows population.

And then for question three, that's split into three parts, A, B, and C, and you need to use data from this particular population pyramid.

And that's a really key skill in geography, to use graphs and maps and extract data from that.

And that's what we're gonna do now.

So 3A, what percentage of the population are females aged 60 to 64? So you have to have a look at that pyramid and find out what the percentage of the population are females aged 60 to 64.

And then 3B, what percentage of the population are males 10 to 14? And then 3C, what percentage of the population are aged naught to four? So pause the video, answer those questions, and then let's come back and see how you got on.

Okay, so how did you do? Let's have a look.

So question one, which axis of a population pyramid shows age groups? The answer is the Y axis? Which axis of a population pyramid shows population? And the answer is the X axis.

Now, question three, 3A, what percentage of the population in that population pyramid are females aged 60 to 64? The answer there is 2%.

3B, what percentage of the population are males aged 10 to 14? The answer there is 6%.

So for those two questions there, A and C, you had to look at which side of the population was female, which side of the pyramid were female and which side were males, and then you had to have a look at that bar and see how far it came across.

So the females age 60 to 64, that comes across 2%, and the males age 10 to 14, that comes across 6%.

Now, 3C, this is a little bit different.

So what percentage of the population are aged naught to four? And the answer there is 18%.

Now, notice this question doesn't ask you about males and females.

This says what percentage of the population, so in order to answer this question, you had to add them together, look at the males and the females and add them together.

So the females age naught to four, that's 9%, and the males age naught to four is also 9%, and so 9% plus 9% is 18%.

And these questions that you've done here, these really highlight the importance of you reading questions properly so that you know what exactly you're gonna be looking for when you're looking at graphs.

Are you looking at one side of the graph, the other side of the graph, or are you gonna have to add some numbers together.

If you've got those right, well done.

Okay, we're gonna move on to the second part of our lesson now.

So what does a population pyramid shape tell us? So the shape of a population pyramid provides information about birth rate and life expectancy.

So now we're bringing in a couple of those keywords that we looked at at the start of the lesson, birth rate and life expectancy.

And that's what a population pyramid can tell us some information about those things.

So a wide base of the pyramid, that means that the base is really, really wide at the bottom, that indicates a large young population, because at the bottom of the pyramid, that shows a young population, and so if that's wide, that means there's a lot of people that are young, so that indicates that there's high birth rates, that there's high rates of people being born.

Now, a wide base is often seen in lower income countries because lower income countries have high birth rates, and that's why often when we look at population pyramids, the population pyramids of the lower income countries have a wider base, because they've got high birth rates.

So this is a population pyramid for Ethiopia in 2019.

It shows a young and growing population.

So as we get go through the ages, as we move down the ages, the population pyramid gets wider and wider and wider.

So there's more younger people than there are older people.

So the population is young and it's gonna be growing 'cause more and more people are being born.

The narrow top, the top is narrow, that indicates a high death rate.

That indicates that lots of people are dying because we've not got very many people who are really old, and a low life expectancy, so people aren't living particularly long, and that's because there are fewer older people.

So there's not very many older people, so that's indicating a high death rate and a low life expectancy.

The wide base at the bottom, that indicates a high birth rate, and that's because there's lots of young people.

So as we said before, the wider base indicates that we've got a lot of younger people and a high birth rate.

So Ethiopia in 2019 has got a high birth rate and a low life expectancy, lots of people being born and people not living particularly long.

So it's wide at the bottom, showing lots of young people, but narrow at the top, showing that there's not very many old people and people don't live very long.

So let's check what we've just looked at there.

What does a wider base on a population pyramid indicate? Does it indicate a high birth rate, a high death rate, or a low birth rate? So pause the video, have a go answering that question, and then come back and let's see how you got on.

Okay, how did you get on? So what does a wider base on a population pyramid indicate? That indicates a high birth rate.

Well done.

Okay, so the shape of a population pyramid also reveals the population's age structure and growth rate, so how many people there are in different ages and how the population is growing.

A narrow base suggests lower birth rates and an ageing population.

So it suggests that there's lower birth rates, and you can see that there's more people as you get older.

And so that population is ageing, there's more older people than younger people.

A narrow base is often seen in higher income countries and higher income countries generally have lower birth rates.

So this population pyramid here is for Russia in 2019.

So this is Russia in 2019.

It shows that the population is ageing, so there's more older people than younger people, which is called an ageing population.

There's more older people than younger people.

The taller pyramid, so this pyramid is quite tall, indicates a high life expectancy.

We've got people who were living in the older category, so the life expectancy is high, people are expected to live for a long time.

The narrow base, that indicates a low birth rate.

This birth rate is lower than 20 years ago, so you can see the birth rate there is much lower.

There's a smaller amount of people in that age than there are in the 20s and above, so 20 years ago, this population pyramid would've had a wider base, but now it's got less people and so the birth rate is lower and it's lower than it was 20 years ago.

Okay, so let's check what we've done again so far then.

What does a narrow base on a population pyramid indicate? Does it indicate a high birth rate, a high death rate, or a low birth rate? So have a go answering that a question, pause the video, write down your answer and then come back and let's see how you got on.

Okay, how did you get on? So what does a narrow base on a population pyramid indicate? A narrow base? That indicates a low birth rate.

Well done.

Okay, so the shape of a population pyramid reveals the population's age structure and growth rate.

This is a steady shape.

This shows that it's balanced growth and each age group is a similar size.

So it's showing none of the age groups are particularly bigger or smaller than the other, so the growth is relatively balanced and each age group is very similar.

And this population is for the UK in 2019.

So it shows a population that has similar number of people in each age group, so you can see there's not great deal of difference between those bars, and so there's a similar number of people in each age group.

The pyramid is relatively narrow in all age groups, indicating a low birth rate, a low death rate, and a high life expectancy.

So you can see that it's a relatively narrow pyramid.

There's no bars that are particularly large and the bars are relatively similar to each other.

So we've got a relatively steady population, a low birth rate, a low death rate, and a high life expectancy.

So let's check what we've done again so far then.

What does a taller population pyramid indicate? Does that indicate a higher birth rate, a higher life expectancy, or a lower life expectancy? So pause the video, and then come back and see how you got on.

Okay, how did you get on? So what does a taller population pyramid indicate? It indicates a high life expectancy.

Well done.

So population pyramids can also have bulges, which are like parts that stick out a little bit more than other parts.

So bulges in the pyramid indicate a higher population in certain age groups, and this is often due to events like baby booms, and we have certain times where lots and lots of babies are born in that particular year, but then that doesn't continue, so it's like a boom at a particular time.

So baby boom is a time when more babies are born than usual.

This can happen after significant events like, for example, like the Second World War.

It can also happen when people feel more hopeful and secure about the future, and that can cause people to be happy to be able to have children because they think they're gonna be able to provide, and so that can cause bulges in that population.

So let's check up with again then.

What does a bulge in the population pyramid suggest? Does it suggest a baby boom, economic decline, or population decrease? So pause the video, answer that question, and then come back and let's see how you got on.

Okay, how did you get on? So what does a bulge in the population pyramid suggest? It suggests a baby boom.

Well done.

Okay, so we're onto our second task of the lesson now.

The task is compare population pyramids from these two countries and identify differences in birth rates and life expectancies.

So you've got two population permits there, country A and country B, and you need to compare those two countries and see if you can pick out the differences in birth rates and life expectancy.

So pause the video, complete this task, and then come back and let's see how you got on.

Okay, compare the population pyramids from these two countries and you were to pick out differences in birth rates and life expectancy.

Let's see how you got on.

So you may have written that Country A has a wide base, which indicates a high birth rate.

Country B has a narrow base, and that indicates a low birth rate.

So that's really good comparing because you've looked at the base, you've said one's wide, one's narrow, and what that indicates.

A wide base indicates a high birth rate and a narrow base indicates a low birth rate.

Country A has a narrow and low top, which indicates a high death rate and a low life expectancy, whereas country B has a wider and higher top, which indicates a low death rate and a high life expectancy.

So again, they're opposites of each other.

One had a narrow and low top, country A, and that it leads to a high death rate and low life expectancy, whereas B had the wider and higher top, indicating a lower death rate and a high life expectancy.

Well done.

Okay, so what have we done today? What have we learned today? A population pyramid shows the age and gender structure of a country's population.

The shape of the population pyramid allows us to see how a country's population is changing over time.

For example, a wider base shows there is a higher birth rate and a narrow base indicates a lower birth rate.

A taller population pyramid shows a longer life expectancy.

Bulges in a population pyramid show a higher population in a certain age group, for example, the baby boom in the UK after the second World War.

Thank you for joining me for today's geography lesson.

I've really enjoyed it and I hope you have too, and I'm looking forward to seeing you next time.