Lesson video

Hello, my name Mr. Tilstone and I'm a teacher.

I'm really excited today.

Do you want to know why? Because I love maths and I get to teach you this maths lesson.

Today's lesson is all about fractions and fractions is one of my absolute favourite things about maths, so I'm really excited.

So will you help me to count down to this lesson? Are you ready? Five, four, three, two, one.

Let's go.

The outcome of today's lesson or the target if you like is, I can name the fraction one half in relation to a fraction of an object, shape or set of objects and explain how I know that it is one half.

So in other words, our lesson today is all about halves and we're going to make you a halves expert.

We've got some keywords.

If I say them, will you say them back? Are you ready? My turn, half.

Your turn.

And my turn, one half.

Your turn.

Those words are going to come up a lot today.

Our lesson today is split into two parts.

The first will be one half of an object and the second, half in different contexts.

But for now, let's focus on one half of an object.

Are you ready? In this lesson, you're going to meet Sofia and Izzy.

Have you met Sofia and Izzy before? They're here today to help us out with the maths.

Sofia and Izzy want to cut this cake so that they can share it.

How could you cut the cake? Mm.

Izzy says, "I love cake." Me too, Izzy, who doesn't love cake? Please can I have the bigger half? Mm, what do you think to that? She wants the bigger half.

And Sofia says, "That's not possible." It is impossible to have a bigger half.

If we cut the cake in half, we will both get the same amount, that's what a half is.

That is a cake cut in half.

Izzy says, "The cake has been split into two halves.

The two parts are equal." And that's what halves are, when two parts are equal.

When the whole has been divided into two equal parts, each part is the called one half.

When the whole has been divided into two unequal parts, each part is not one half.

So let's have a look at an example of that.

We could cut the cake like this.

"My part is bigger," says Izzy, "So it's not one half," because it's not equal.

"My part is smaller," says Sofia, "So it is not one half." Let's practise saying Sofia's sentence to help remember what one half means.

Right, I'll say it and then we'll say it together and then just you'll say it.

Are you ready? I'll say it first.

When the whole has been divided into two equal parts, each part is one half.

Okay, do you think you've got that? Could we do that together? Are you ready? Let's go.

When the whole has been divided into two equal parts, each part is one half.

Very good.

Now, just you after three.

One, two, three, go.

Great, so we are on our way to being halves experts.

We know that when you split something into two equal parts it's one half.

Sofia says, "Did you know that one half is a fraction?" Did you know that? It is.

Izzy says, "So a fraction shows that a whole has been divided into equal parts." Yes.

"That's right," says Sofia, "Well done, Izzy." Let's do a little check.

Izzy has tried to say Sofia's sentence, the one that we just said, to describe one half, but she has forgotten some of the words.

I wonder if you could help her? Can you remember some of the words? Let's see what she can remember.

She says, "When the whole has been divided into parts, each part is." Can you fill in the parts that Izzy can't remember? Tell a partner, pause the video.

Did you manage to complete that sentence? When the whole has been divided into two equal parts, each part is one half.

Let's say that together one more time, are you ready? Let's go.

When the whole has been divided into two equal parts, each part is one half.

Izzy and Sofia share some food.

That's nice, isn't it? They are checking if each part is one half or not.

Will you help them out? What do you think? Is each part one half? Izzy says, "I can see the whole has been divided into two equal parts." That means that each part is one half.

That would be fair sharing, wouldn't it? I wouldn't mind which part I got, because they are both the same size.

They are both one half.

What about this, is each part one half? Let's see how they cut the pineapple.

Mm, can you see halves? Is each part one half? Izzy says, "I can see the whole has been divided into two unequal parts." So it has been divided into two parts, but not two equal parts.

They're unequal, they're not the same size.

It wouldn't be fair sharing, would it? Sofia says, "That means that each part is not one half." Let's have another look.

Let's have another go.

What about now, is each part one half? Has it been divided into two parts? Has it been divided into two equal parts? Izzy says, "When it is cut this way, the whole has been divided into two equal parts." That means that each part is one half.

That would be fair sharing, wouldn't it? That is a half.

What about this one? Do you think each part is one half? Let's have a look.

What about that, is each part one half? Has it been divided into two equal parts? What do you think? Izzy says, "I can see the whole has been divided into two equal parts." That means that each part is one half.

That would be fair sharing.

Let's have a little check.

Do you think that each part is one half and how do you know? So are you ready? Let's cut it and you tell me, are they one half each part? Let's have a look.

Okay, pause the video and discuss that with your partner.

What do you think, were they one half? Was each part one half? I can see it's been divided into two parts, but are they two equal parts? The two parts are not equal, so each part is not one half.

I think the part on the right is bigger than the part on the left, so they're not equal.

Sofia says, "I wonder how you could cut it so that each part is one half?" Have you got any ideas, what would you do? If you were cutting that pear, how would you make sure that it was in halves, that each part was one half? You could cut it like that.

That would be one half.

Each part would be one half.

Izzy says, "The whole has been divided into two equal parts, so each part is one half." You're doing really, really well and I think you're ready for some practise.

What do you think? Number one, tick the objects that have been split in half.

So I can see looking at those objects some of them have been split into two equal parts and some have not been split into two equal parts, they've been split into two unequal parts.

So we're looking for the ones that have been split in half.

And can you explain to a partner why you didn't tick some of those pictures? Number two, complete the sentences by writing one half or not one half.

So we've got the start of the stem sentence, each part is.

And make sure you spell those words properly please, they are there on your sheet.

Izzy says, "See if you can find any more objects around you that have been split into two halves." Have a little look around your classroom.

Pause the video, have great fun with that and I will see you soon.

Welcome back, let's have a look at some answers and let's see how you're getting on.

Are you a halves expert yet? Let's find out.

So the objects that have been split in half.

That one has, that's two equal parts.

This one has, that's two equal parts.

This one has, that's two equal parts.

This one has, that's two equal parts.

I did not tick the leaf, because the two parts are not equal.

They're not the same size, so I know it has not been split into halves.

And number two, you were writing one half or not one half after each one.

So let's look at the apple.

Each part is one half.

They're the same size.

And the burger, each part is not one half.

They're not the same.

And the cheese, each part is not one half.

They're different sizes.

And the cake, each part is one half.

They are the same size.

Izzy says, "I found another example.

My sandwich in my lunchbox was cut into halves." Ooh, got an example.

Each part was one half.

What did you find? Did you manage to share it with your classmates? You are doing really well and I think you're ready for the next cycle and that is, half in different contexts.

Sofia has been practising finding half in lots of different ways, and you can see three examples there with food.

Each of those has been split in half.

Each of those has got two equal sized parts.

And Sofia says, "I'm an expert at recognising half now." What about you, do you think you're an expert yet? Izzy says, "That's great.

Maybe you could give me a little help?" Izzy's not quite there yet.

She's on her way to being an expert.

When the whole has been divided into two equal parts, each part is one half.

So have a look at that triangle.

Would you say that's been divided into two equal parts? What do you think? Has this shape been split into halves? Sofia says, "No, there are two parts, but they're not equal." So you can't say they are halves, they're not halves.

What about this time? Has that triangle been split into two equal parts? Is it divided into two equal parts? Is each part the same size? What is I split it this way? Sofia says, "Yes, that's right, now each part is the one half." Sometimes there is more than one way to find half a shape.

So here's an example.

This is a square that's been split in half and the same square has been split in half, but a different way.

And the same square has been split in half a different way again.

And again, that's an unusual way this time, isn't it? Look at that.

And again with a curved line.

And one more time with this zig-zaggy line, but in each of those examples, that square has been split in half.

Each of those parts is equal, each part is the same size.

"These all show half, because the whole has been divided into two equal parts each time," says Sofia.

Okay, let's have a look at a different shape.

We looked at a square and let's look at a pentagon.

What do you think? Has the pentagon been split in half each time? Izzy thinks she has found three different ways to divide the shape in half.

What do you think, has she succeeded? Two of those are right, but you've made one mistake.

Ah, I've spotted it, have you? Let's have a look.

She says, "Let me have another go." Good for you, Izzy, that's what good mathematicians do.

When they make a mistake, they try again and they try something else.

Let's have a look.

Okay, she's made a change.

What do you think now? Now all the shapes have been divided into two equal parts, well done, Izzy.

So now none of those pentagons has got a small part and a big part.

They've got equal sized parts, they're in halves.

Each part is one half.

Okay, you're doing really well.

Let's have a little check to see just how well you are doing.

Which images show half of a shape? And there might be more than one answer here.

Okay, pause the video and explore.

This first shape has been split in half, so each part of the shape is a half.

The second shape has also been split in half, each part of it is a half.

And finally, the fourth shape has been split into half.

It's got two equal sized parts.

All of these shapes have been divided into two equal parts, so they all show half, but this shape has been divided into two unequal parts, so it does not show half.

It is two parts, but they're not halves.

They're not the same size.

Sofia has been practising finding half in lots of different ways.

Let's have a look at one.

One half of the otters are on the land.

Can you see that? And one half of the otters are in the water.

Yes.

What about now, are one half on the land and one half in the water? No, now some of the otters have climbed out of the water.

This image does not show half.

How do these cakes show half? How could you describe these cakes as showing halves? One half of the cakes have a cherry.

One half of the cakes do not have a cherry.

So they're equal sized groups.

What about now? Another cherry has been added.

Is it showing half still? No, it's two groups, one's got cherries on and one hasn't, but they're not equal sized.

One's got three cakes in and one's got one.

They're not equal sized.

That wouldn't be sharing fairly, would it? Let's have a look at these penguins.

How do these penguins show half? What do you think? One half of the penguins are at the top of the hill and one half of the penguins are at the bottom.

And they're equal sized groups.

Three at the top, three at the bottom.

Those groups are the same size.

Let's have a look at this.

Wee! And another one, wee! That looks fun, doesn't it? What can we say now about the groups? Now some of the penguins have slid down the hill.

This image does not show half.

Those groups are not equal sized anymore.

Let's have a little check.

Which images show half and how do you know? So have a really good think about that and pause the video.

One half of the cats are walking and one half are sitting.

The two groups are equal.

You might've talked about the colours of the cats as well, but either way, they're equal sized groups.

The group size is two cats.

This stick of blocks has been divided into two equal parts, so each part is one half.

Each of those parts has got four blocks, they're equal, they're the same size.

But these don't show half, because the two parts are not equal.

So let's look at the cats.

Whether we group them by colour or whether they're standing up or sitting down, one group's got one cat in and one group's got three cats in.

So they're not equal, they're unequal, they're not showing half.

And the same with the blocks, they're not equal, they're unequal.

One of the groups has got more blocks in than the other.

There's a bigger group and a smaller group, so we can't say they're halves.

It's time for some final practise.

I think you're ready for this.

Find three different ways to show half and not half of these shapes.

So you've got three different circles and three different rectangles, each time, can you divide them into halves and then the other set, into not halves? So not equal sized.

And number two, which images show half and how do you know? So have a really good look, see what you notice.

Is it half or is it not? And see if you can explain.

Number three, use six objects that are around you to show half.

And it might be some maths equipment for example around you or it might be something else in your classroom.

Sofia says, "I will use a toy farm." That's a good idea.

One half of the animals could be outside and one half could be in the shed.

Great idea, what could you come up with? Izzy's got a different idea.

She says, "I will use dolls.

One half could be laying down and one half could be sitting." Aah, that's different, isn't it? Very good, I like that.

Okay, so be creative.

Just like the girls were here, you be creative too.

Think of as many different ways as you can to show halves.

Can you change the arrangement of your objects so that they're not showing half? Explain to your partner how you know that it is not half anymore.

So show some halves and then show some not halves.

Have great fun exploring that and I'll see you soon for some feedback.

Pause the video.

Welcome back, let's have a look.

Now, there's lots and lots of different ways you could've done this.

This is just a few examples.

So that's half.

That's half and that's half.

So each of those circles has been split into two equal sized parts.

Now let's split the circles so that they're not half.

So we've got two parts here, but they're not equal parts, they're unequal, so that's not half and that's not half, they're unequal and that's not half, they're unequal.

What about the rectangles? Let's start with the halves.

They are halves, they're equal sized.

They are halves, they're equal sized but different.

And they are halves, they are equal sized but different again.

What about not half? Two parts, unequal.

Two parts, unequal.

Two parts, unequal.

None of those are halves.

And which pictures show half and how do you know? A doesn't show half, because two groups of otters are not equal, so that's not half.

One of the groups has got two otters in and one's got three, so that's not half.

B, yes, that does show halves, because one half of the bears are inside the cave and one half are outside, and it's the same number inside as outside.

And C, one half of the frogs are on the logs and one half are on the ground, so they are in halves.

For D, the stick of blocks has been divided into two equal parts, so each part is one half.

And E, nope, the groups of penguins are not equal.

There are two groups, but they're not equal, they're unequal groups.

There's more in one than the other, that's not half.

And the same for F, team one is bigger than team two.

It's got more children in, so the two teams of children are not equal, they're unequal.

It is not half.

And six objects that are around you to show half.

Were you creative here? Did you come up with some really imaginative examples? Sofia says, "I used a toy farm.

One half of the animals are outside and one half are in the shed." That's a good idea, that showed halves.

If I move any of the animals outside or move any into the shed, I am no longer showing half, because my two groups are not equal.

Let's see.

Yes, now one of the sheep has moved, they're unequal groups.

Now one group's got two in the inside and one group's got four on the outside.

They are unequal, they are not halves.

Now they're halves again.

Now they're not halves.

We've reached the end of the lesson.

I've had so much fun exploring halves with you today and I hope you've had fun too.

Today we've been recognising and naming the fraction one half.

When the whole has been divided into two equal parts, each part is one half of the whole.

You can find of objects, shapes and sets of objects, and you've been doing that with all sorts of different things today, including food.

So my final question to you is this, are you a halves expert? Give me a thumb up if you are a half expert? Yeah, I think you are.

You've done amazingly well today.

I can't wait to spend another maths lesson with you, because I've had so much fun today.

I hope you enjoy the rest of your day and that you have some great lessons and that you work really hard.

Until the next time, bye-bye.