Lesson video

Hi, it's me, Miss Jones.

Welcome to your maths lesson today.

Hope you're ready to get started.

Let's have a look at what we're doing.

In today's lesson, we're going to be learning how to calculate unit fractions of quantities.

Now, you may not know what unit fraction means.

Well, it's any fraction with a numerator of one.

For example, 1/2 or 1/4.

We're going to start though with a just describing any fraction of a quantity.

So we're going to look at some representations and describe the fraction that we see.

Then we're going to specifically look at finding a unit fraction of a quantity.

You've got a task today and a quiz to finish off.

You will need something two write with and something to write on.

So a pencil and piece of paper will do just fine.

If you haven't got anything, go and get something now and pause the video.

Then come straight back.

Okay, let's have a look at this group of people or set of people.

What's our whole? Well, we've got eight people, so we could say our whole is eight and we're going to find fractions of that quantity of people.

Let's look at our questions.

What fraction of the group are wearing stripes? Well, we've got eight people together.

So I'm just going to draw my vinculum, then my denominator, eight.

We've got eight parts, eight people.

Wearing stripes, I've got one, two, three.

So our numerator needs to be three.

We can say 3/8 of the people or the children are wearing stripes.

What fraction of the group are wearing hats? Let's see if you can write down this one quickly.

Well, again what's our denominator? It's eight.

Our whole is eight.

And I can see that four of them are wearing hats.

So our numerator is four.

Now, you might also recognise that four is half of eight.

We could also write this as 1/2 of the people are wearing hats.

Now, 1/2 is a unit fraction, which we're looking at today.

And we'll look a little bit more at later on.

Final question.

What fraction of the group are wearing a green t-shirt? What do you think? Okay, let's start with our vinculum.

Then our denominator needs to be eight again because we've got eight people.

And just one of them are wearing a green t-shirt.

1/8 of the people are wearing a green t-shirt.

Okay, looking at this, now we have a set of cylinders here.

Again, I'm going to ask you what fraction is shaded? First of all, think about writing a fraction.

We need our vinculum.

We have six parts all together, six cylinders.

And I can see that two of them are shaded, so our numerator needs to be two.

What about this one? We're drawing a fraction or writing a fraction, so we need our vinculum.

We have this time 10 parts all together.

Our whole is 10.

And one, two, three, four, five of them are shaded.

5/10 are shaded.

Okay, it's your turn to have a go at that.

So for each picture, can you write down the fraction that's been shaded? Okay, so for this first one, what's the fraction of the octagons that's shaded? Okay, pause the video and have a go at each of those.

We'll go over the answers when you get back.

Okay, hopefully, you've had a go at writing down your fractions.

For this first one, we need to first of all, 'cause we're writing a fraction, put our vinculum in, then think about our denominator.

How many parts are there in the whole? There were 16 and four of them were shaded.

So we're identifying four of them.

So four is our numerator.

Let's go over the other three.

So again, writing a fraction, we've got 15 parts all together and three of them are shaded.

3/15 of the moon shapes have been shaded.

This third one, our denominator is 12.

There are 12 parts and eight of them have been shaded.

8/15, sorry, 8/12 of the cubes have been shaded.

And finally, at the bottom, we've got eight and six of them have been shaded.

6/8 have been shaded.

Okay.

This time, I've got some counters.

And I'm going to think about what fraction of them are green? Now, I've split these in half really because you've got two groups of six.

So I could say that half of the counters are green.

I know that half of 12 is equal to six because of my division facts.

So I can see here and confidently say 1/2 of them are green.

What other way could I write the fraction of the green counters? Well, I know there are 12 and six of them are green, so I could also say 6/12 of the counters are green.

1/2 is the same as or equivalent to 6/12.

So 6/12 might be one way of writing it and 1/2 might be another.

Now, 1/2 is our unit fraction because the numerator is one.

Let's look at this one.

Here I've got 12 counters all together.

But I can see that two are shaded.

I've also split these into six groups.

We could say that one group out of our six parts have been shaded.

1/6 of the counters are blue.

That's a unit fraction.

I could also say that 2/12 of the fraction of the counters are blue.

Two out of 12 counters are blue.

Here, my whole is the amount of counters and here my whole is the amount of groups I've made.

These are equivalent, 1/6 is equal to 2/12.

Let's look at the images we looked at at the beginning of the lesson.

We said that this image was showing 2/6.

Two were shaded out of six cylinders.

Six is the whole because there are six cylinders all together.

However, this time, I've put in some dividers here.

So you can see I've got three groups.

So we could say here our whole is three and one of the groups is shaded.

How might we write that? We could write that as 1/3.

Three groups all together, one of the groups is shaded.

2/6 is equal to 1/3.

Now, 1/3 is the unit fraction here because the numerator is one.

Okay, looking at this next one, earlier we identified the fraction shaded as 5/10.

There were 10 equal sized parts and five of them were shaded.

It makes sense.

This time, I've put a line down the middle here to separate this into two groups.

Now let's look at the amount of groups.

We've got two groups all together and one of them has been shaded.

We could write this as 1/2, 1/2 of the shapes have been shaded.

5/10 is equivalent to 1/2 and if you notice, five is half of 10, which is another clue to seeing that these are equivalent to 1/2 as well.

Okay, so for your task, I want you to take each of those images and write an equivalent fraction, some of which might be unit fractions.

Okay, once you're done.

Come back here and we'll go over the answers together.

Okay, hopefully, you completed this task.

Now, we looked at some of these together earlier.

So for this first one, we said earlier that the shaded part was representing 4/16.

We could also say that that's equivalent to 1/4.

We've got four groups and one of them has been shaded.

For the next one, we said earlier that the shaded part was 3/15.

We could also say that the shaded part is 1/5.

There are five groups and one of them has been shaded.

For the next one, earlier we said 8/12 but we could also say that 2/3 of the cubes have been shaded.

There are three groups and two of them have been shaded.

And for this final one, we could say 6/8 have been shaded.

There are eight shapes and six of them have been shaded.

We could also say 3/4 have been shaded.

There are four groups and three of them have been shaded.

How did you do? Okay, if you're ready, it's time to take the quiz.

Thanks, everyone.