# Lesson video

In progress...

Hello, everybody.

My name is Mr. Kelsall, and welcome to today's lesson on understanding percent in the world.

Before we start, you will need a pen, a piece of paper, and also a quiet place somewhere that you're not going to get disturbed.

Don't forget to put away any sort of distractions.

For example, put your phone on silent or move it away completely.

Pause the video, and then when you're ready, let's begin.

Today's lesson is about understanding percent in the world.

We're then going to link facts to percentage.

We'll create some percent statements, and then it is quiz time.

You'll need a pencil and a piece of paper.

And we're going to start with, we'll be looking at percent, which is made up of per cent and we'll be looking at the percentage symbol.

We'll be talking about division and divided and equal parts.

We'll look at fractions and decimals, and we'll use the word hundredth and equivalent.

A little bit of revision to begin with.

Cent means 100 and percent means per 100.

We know that with fractions we can link percent to fractions and all sorts of decimals.

For example, 50% is one half.

It's also 50 out of 100, and it's also 0.

5.

25% is one quarter or 25 out of 100, and it's 0.

25.

20% is one fifth, and it's 20 out of 100, which is 0.

2.

We can go on to other percentages as well.

For example, 10% is one tenth, which is 10 out of 100 and 0.

1.

Our new learning for today.

Match the fraction and the percentage equivalent.

Can you justify and can you clearly explain each answer, and then can you order them from the smallest to the largest.

Pause the video, and then when you're ready, press play to continue.

I know that 10% is one tenth or it's 10 hundredths.

I know 20% is one fifth.

I know that's two tenths, or I know it's 20 hundredths.

25% is one quarter or it's 25 hundredths.

50% is one half, or it's 50 hundredths.

And 75% is three quarters or 75 hundredths.

Now, look at this statement.

30% of the world population are children.

We hear things like this all the time but what does it actually mean? And what's this as a fraction? And does it mean that there are 100 people in the world and 30 of them are children? Pause a minute, pause the video.

Have a think about these statements and then press play when you're ready.

Well, we know that it can't mean that there are 100 people in the world, because there's more than a hundred people in most schools.

So we know that it's something a little bit different.

But what it actually means is that if there are 100 people, 30 of them would be children.

But if there were 200, 300, 400, a million, 4 million, then 30%, or that proportion, that part, would be children.

As a fraction, we can write 30% as 30 over 100 and we can simplify it to give it three tenths.

Now I want to say a little bit more about this idea of 30% and that there's not 30 children in the entire world.

Just imagine for a moment, your school has 100 people.

And let's say 10% of those people are teachers, and 90% are children.

That's a great way to compare.

You can say, I've got 90% children, and 10% teachers.

However, what if your school had 200 children? I could say, well, I've got, how would you compare that? Would you say you've got 10 teachers and 90 children? Because that doesn't add up to 200 children.

You'd have to think what proportion of those 200 children are teachers and what proportion are children.

So if it was the same thing, I'd say, well, I've got 20 teachers and 180 children.

And if I wanted to compare the school with 200 children with a school which had, I don't know, 50 children, it'd be really difficult to compare these numbers because we need to sort of talk in units which are exactly the same measurements.

And when we talking in percentage, we're talking what proportion of the whole thing is one thing or another thing.

So what proportion of the whole school is teachers? What proportion of the whole school is children? And if we take the whole thing as 100%, then we can say, oh this part is teachers, this part is children.

And we can do that with anything.

So don't ever get confused that 30 out of 100 means that there are 30 people, 30 children in the entire world.

Let's continue with this idea and let's develop it and generate some statements about percentage.

So, look at this.

76% of the world population have electricity.

What other statements can we say from this? Pause the video.

When you're ready, press play to continue.

Most obvious statement is that if 76% of the world population have electricity, then 24% do not have electricity.

The other thing to say is that quite a large number of people have electricity, but actually there's a lot of people that don't have electricity.

This brings us to the develop learning of today's lesson.

Look at this map.

This is the percentage of populations around the world.

Have a look at your 100 grid.

Print it out if you need.

Can you shade in these percentages onto your 100 grid? And ask yourself, do they add up to 100%? Pause the video, and when you've done this, press play to continue.

I've shaded in my 100 grid and I can see that the population, this adds up to 100%.

Dark blue is Asia.

Orange is Europe at 43%.

Blue is North America.

Pink is 11% with South America.

Africa is green on 9%, and Australia is 6%.

This brings us to our independent task for today.

Use the information on the screen to generate statements about these Olympic sports.

So the first columns are all to do with age range.

And that's the percentage of athletes.

The next pie chart shows 52% of men and 48% of women.

And you've also got 100 grid.

You might want to shade the 100 grid with the athletes' ages and the percentage of ages so you can see that it adds up to 100%.

Pause the video, and when you're ready, press play to continue.

You could ask yourself some questions.

For example, you could say, what percentage of people were under 20 years old? I can see 10% are 16 to 20, 0% or under 15, so in total 10%.

I could say, what percentage of people are over 31 years of age? I can see 19% are aged 31 to 40, and 1% is aged over 40.

So in total that's 20%.