# Lesson video

In progress...

Hello everybody, my name is Mr. Kelsall and welcome to today's lesson about understanding percentage.

Now before we start, you will need a pen and a piece of paper.

Also, please try and find a quiet place somewhere that you're not going to be disturbed and don't fear to remove any distractions.

For example, put your mobile phone away or turn down in silence.

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

Today's lesson is all to do with understanding percentage.

First thing we will do is look at the idea of cent and what it means.

We'll then try to understand per 100 and then we'll look at different ways to represent percent.

After that is quiz time.

I've already mentioned that you need a pencil and piece of paper.

The star words today is percent and per cent.

We'll look at the percent symbol.

We'll use fractions, decimals.

Have a look at the pictures on the screen.

What words can you use to describe these clues? And what's the connection between the answers? Pause the video and when you're ready, press play to continue.

Well the first one a person who lives a 100 years beyond a 100 years old is called a Centurium.

An insects with many likes is called a centipede.

A hundred cent is equal to one US dollar.

A century is a score of a hundred or more in cricket.

And a hundred cent is equal to one Euro.

So the connection between all of them is the idea of a hundred and the word cent.

Have a look at the picture there are a hundred people in a section of a stadium.

27 of them are children.

How can we describe this? Pause the video press play when you're ready.

You might have thought of lots of ways to describe this, you might have described it through words and said there are 27 children per 100 people.

There are 27 children out of a hundred people.

You might have used fractions to describe it as well.

You might have said there are 27 out of a 100 or 27 hundredths.

There's lots of different ways to describe it.

I also want to show you how we can represent this in equipment that we use in skill.

And they're red and white and each section represents 10 beads.

So if I was to represent 27 children on this hundred bead string, I'd represent first red one, 10 red ones then 10 white one, so I've got 20 beads so far.

Then it counts long two one, two, three, four, five, six, seven, and that's 27 beads.

Which we're going to use to represent 27 children.

I know if there are 27 who are children, that means I've got another three to take me up to 30.

And I've got another 10, 20, 30, 40, 50, 60, 70.

So I've got a total of 73 who are not children.

And I can check this because does 27 and 73, add up to a hundred? Yes it does.

So we use bead strings quite a lot because there are a hundred beads on this, and we can use this quite a lot when we're talking about percentage.

We'll also talk about hundred grids which are useful with percentage because it's per 100.

So just so you understand a bead string, one bead is one part out of a hundred and there are a hundred equal parts.

So it's 1% of the whole string.

So if I ever look at this first one, this is my 1% just here.

Well if I know that's 1% I've got 10 here, so I can say that is 10%.

So my one bead represents 1% of the whole beach string and my 10 beads represent 10% of the whole bead string.

So look here the next idea.

What percentage of the whole string is 60 beads? Take a minute to think about that, five seconds.

So you should have identified that 60 beads out of a hundred beads is that 60%.

We can mark and we know we've got 10, 20, 30, 40, 50, that's my 60 beads, which is my 60%.

And again for question two, what percentage of the whole string is 43 beads? 10, 20, 30, 40,43.

That's 43 parts out of a hundred, which is 43% In terms of vocabulary, we often describe this as 30% means 30 out of a 100.

So 30 beads is 30% of the whole string.

Try saying that with some of these other ones.

So your next percentage is 21%.

So say it with me, 21% means 21 out of 100.

21 beads is 21% of the whole string.

Pause the video and try practising that stem sentence with the remaining percentages on the screen.

When you're ready, press play to continue.

That brings us to our develop learning for today.

We're now going to move on to the hundred grid.

This grid has a hundred equal parts.

14% means 14 out of 100, which can be written as 14 the slash which is the vinculum 100.

So the fraction is 14 over 100.

If you have a look on the screen, this has been done in a few different ways.

I can say I've got one, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14.

On the green, the square which is shaded in with green squares.

I can count these 10 straight away because I know this hundred grid is a 10 by 10 square.

So I've got 10, 11, 12, 13, 14.

So both of these mean 14%.

14% means 14 out of a 100, which can be written as 14 over 100, Pause the video and see if you can represent this 14% in different ways.

When you're ready, press play to continue.

Now, there are a 100 people sat in a section of the stadium.

14 people support Switzerland, 40 different people support the US of A.

How could we re represent this on the hundred grid? Pause the video and have a go with it.

Once again, there are a number of different ways to do it, but I'm going to start with my there's 10% 11, 12, 13, 14.

So I know that this represents Switzerland.

Then the 40%.

Now I could start at the next square along, but I think that's going to be a little bit trickier because I've got a nice even number.

I've got 40 people.

Now I know that each of these rows is 10 squares along.

So for 40, I could say 10, 20, 30, 40, take a moment to think.

What is the total percentage representing Switzerland and the USA at the moment? Also think what is the percentage which do not represent these two countries? Pause the video have a think when you're ready press play to continue.

40 and 14 add to 54%.

That means that the remaining section do not represent Switzerland or USA.

Also I'm looking for a number bond which adds on to 54 to give me a 100.

Well if I do four add six, it takes me to 60 and then I need to add another 40 to get to 100.

So I'm looking for 46% and that should be the remaining part of the 100 grid.

Let's check it and see.

One, two, three, four, five, six.

I've got my 6% there.

16, 26, 36 and 46% fills up completely.

So I know that I've got a total of a 100 people a 100%.

Will continue to develop this learning.

The people sat in these seats, all brought an Olympic flag.

What percentage of the people brought a flag? And what percentage of the people did not? Pause the video when you're ready, press play to continue.

I can count all the parts which are shaded, and I'll do that really quickly.

One, two, three, four, I've counted to a total of 44 dots, which is 44 out of 100, which we also call 44%.

So that's the percent of people who bought a flag.

What percentage did not buy a flag? Well I know that 44, if I add on six it takes me to 50.

If I add on 50 it takes me to a 100% I think that 56% of people did not buy a flag.

Well let's check it and let's add up these numbers.

I did these off video, and I've got a 16, 16, 12, and 12.

And when I add them up that gives me 56.

So I know 44% bought flags and 56% did not buy flags.

Assignment to shade all the multiples of seven in the grid and find the percentage that are multiples of seven, as well as the percentages that are not multiples of seven.

On the second one, you need to shade in all the square numbers.

Remember a square number is one times one, two times two, three times three, four times four, and so on.

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

I know from my multiples of seven, 13% are multiples of seven and 87% are not multiples of seven.

For my square numbers, 10% are square numbers and 90% not square numbers.

And that brings us to our independent task.

Read all the questions on the screen, pause the video and then when you're ready, press play for the answers.

I've marked on and I know I've got a total of 93% who support these three teams, which means I've got 7% who do not support these three teams. And have a read of the corrections, pause the video and when you're ready, press play to continue.

In total 90% are apples, bananas and oranges, which means that 10% are none of these.

To find out in total 37% are water, milkshake or orange juice, which means 63% are the remaining drinks.