Lesson video

Hello everybody.

My name is Mrs. Johnson.

I am so happy to be here today to help you with some of your maths learning.

I hope you are ready to work hard and have lots of fun.

Let's have a look at what we're going to be learning about today.

This lesson is called Discuss and Compare 3D Shapes.

It comes from the unit shape, Discuss and Compare 2D and 3D Shapes.

By the end of this lesson, you will be able to discuss and compare the properties of 3D shapes.

That means you will be able to look at some different 3D shapes and think about what do they have that's the same and what do they have that's different, so get ready to be looking at some 3D shapes really carefully.

There are some key words that are really important for this lesson today.

We're going to practise saying them now.

It will be my turn first and then it will be your turn.

Ready, my turn.

Compare, your turn.

My turn, faces.

Your turn.

My turn, vertices.

Your turn.

My turn, edges.

Your turn.

Well done.

Listen carefully for those words today, because they are going to be really important for your learning.

There are going to be two parts to this lesson today.

To begin with, you are going to learn how to compare cylinders and then in a little while you are going to learn how to compare different 3D shapes.

Let's start with comparing cylinders.

There are two friends who are going to help you in today's lesson.

Their names are Sam and Jacob.

Look out for Sam and Jacob today and listen carefully to the things that they have to tell you.

Look at all of these shapes.

Jacob wonders how he could describe them.

I wonder if you have any ideas.

How might you describe these shapes? That's a good question, isn't it? Something interesting to think about? Sam says, "I wonder what shape these are?" Do you know what shape these are? I wonder if you've learned about them before.

Let's have a look.

These are all cylinders.

Well done if you remembered that and you were thinking about cylinders.

Jacob knows that a cylinder has two circular faces and one curved surface.

You can see that on all of these cylinders, can't you? Sam is thinking about a really good question.

She says, "If all of these shapes are cylinders, "then why do they all look different?" Sam is thinking that if they're all cylinders, they should all look the same.

What do you think? Let's have a look.

Jacob says, I think that some of these cylinders are wider and some are narrower.

We can see that here, can't we? This cylinder is wider and this cylinder is narrower.

Sam thinks that some of these cylinders are shorter and some are taller.

We can see that here, this cylinder is shorter and this cylinder is taller.

Perhaps that is why these cylinders all look different, because some are taller and some are shorter.

Some are wider and some are narrower.

Let's see if you can complete the sentences to describe these cylinders using the words in the box, taller, shorter, wider and narrower.

Can you complete each sentence by using one of those words? Pause the video and have a go now.

Okay, let's have a look at how you could have completed these sentences.

The first one says A is um than B.

You need to look at cylinder A and cylinder B.

What do you notice about A compared to B? Maybe you said that A is shorter than B.

You could have also said that A is wider than B.

On the second sentence, B is than C.

You could say B is taller than C or you could say B is wider than C.

On the next sentence, C is um than A.

You could say C is taller than A.

You could also say C is narrower than A, and on the last sentence you could say C is shorter than B, and you could say C is narrower than B.

Well done if you are able to use those words in the box to try and fill in these sentences correctly, great job.

You know that you can compare cylinders.

You can look for cylinders that are similar and cylinders that are different.

Some might be quite similar to each other and some might be very different.

Let's have a look at that a little bit more.

Jacob chose these two cylinders, because he thinks they are similar.

That means they are alike.

Jacob says, "I think that these two cylinders are similar "because they are both short and wide." Sam thinks that these two cylinders are similar.

I wonder if you can think, why does Sam think that these cylinders are similar? Let's have a look at her reason.

Sam says, "I think these two are similar, "because they are both tall and narrow." Oh, I wonder if that's the same reason that you are thinking of.

Now, Jacob has chosen two cylinders because he thinks that these are very different to each other.

Do you think these two are very different to each other? Let's see Jacob's reason.

Jacob says, "One is tall and narrow, "the other is short and wide." That's why he thinks they are very different to each other.

I wonder if you can see any more cylinders that you think are very different to each other.

Let's check if you can look carefully at cylinders.

You've got A, B, C, and D.

Jacob says, "I think D looks like a smaller version of B.

"They are similar." Sam says, "I think B looks like a taller version of A.

"They are similar." Pause the video and decide who do you agree with? Good thinking, let's have a look and see if you are right.

Jacob's description was correct.

He said D looks like a smaller version of B.

If you look carefully at D and B, you can see that D is a smaller version of B.

We can say that they are similar, because they are both tall and narrow.

Now, let's think about what Sam said.

She said B looks like a taller version of A.

That's not right, is it? Look carefully at B and A.

B is not a taller version of A.

We could say that A is much wider than B.

We could also say that B is much taller than A.

B is also narrower than A.

These two cylinders are not similar, are they? We agree with Jacob's description.

You know that you can compare cylinders, using words like taller, shorter, wider and narrower, but Sam would like to know is there another way that we could compare cylinders? I wonder if you could think of any other ways.

We're going to have a look at that now.

You can compare cylinders by thinking about how much space each cylinder takes up.

Pedro is here and Pedro has bought some new drinking glasses to pour his milkshake into.

I'm not sure if you've met Pedro before, but Pedro's favourite drink is milkshake and now he's bought some new glasses to be able to pour his milkshake into.

That's very exciting for Pedro.

Because Pedro loves drinking milkshake so much.

You are going to help him find out which glass would hold the most milkshake.

Pedro loves milkshakes that he would like a really big drink of it.

Which glass would hold the most milkshake? I think Jacob and Sam are going to help Pedro find which glass would hold the most milkshake.

I wonder which glass you think they are going to choose.

Let's have a look.

Jacob says, "I can see that this is the tallest glass, "but it is very narrow." Sam says "That glass would not hold the most milkshake." Even though it's a tall glass, it's very narrow.

I don't think you'd get very much milkshake in there.

That one doesn't look like it's going to hold the most milkshake, does it? What about these two? Jacob says, "I think that one of these two glasses, "would hold the most milkshake." Which one do you think it would be? Sam thinks that most of the other cylinders, look like they would fit inside this one.

That means that this one is the largest.

Sam has also noticed that this one looks like it takes up the most space.

Now, I think Jacob's going to help Pedro decide.

He says, "Choose this glass Pedro.

"It will hold the most milkshake." Jacob and Sam looked really carefully at all those different cylinders to find the largest cylinder, the one that would hold the most milkshake.

Let's check if you can look carefully at cylinders.

This time you are going to find the glass that would hold the least amount of milkshake.

This can't be for Pedro, can it? Maybe this is for somebody who's eaten lots of food and they're feeling quite full up, so they only want to have a little drink of milkshake.

Which glass would hold the least amount of milkshake? Do you think it's A, B or C? Pause the video and have a think now.

Let's have a look and see how you got on.

The glass that would hold the least amount of milkshake is B.

Jacob noticed that B is the tallest glass, but it is also the narrowest.

Sam noticed that B would hold the least amount of milkshake, because it looks like it takes up less space than the other two cylinders.

Well done if you were thinking about how much space the cylinder takes up.

That's how we know which cylinder is the smallest.

It's the one that takes up the least amount of space.

Now, it's time for you to do a little bit of practise of comparing cylinders.

First, you are going to use playdough to build two shapes that look like cylinders or you could choose two cylinders of your own to compare.

Then I would like you to complete these sentences in as many ways as you can, using the words from the box to help you.

The cylinder is um, than the second cylinder and the second cylinder is um than the first cylinder.

Jacob says, "Remember that a cylinder "has one curved surface and two circular faces." That will help you when you are making your shapes from the playdough.

On the second question, I would like you to have a look at all of these cylinders and choose two cylinders that you think are similar.

See if you can explain to your partner why you think that those two cylinders you've chosen are similar.

Then you are going to choose two cylinders that you think are very different.

Again, explain to a partner why do you think the two that you have chosen are very different? You are going to pause the video and have a go at those two questions now.

Off you go.

Let's have a look and see how you got on.

On the first question, you might have made some cylinder shapes out of playdough a bit like this.

These are the shapes that Sam made.

I wonder if yours looked a little bit like this.

This is how Sam completed her sentences.

The first cylinder is wider than the second cylinder.

The second cylinder is narrower than the first cylinder.

Sam also said the first cylinder is shorter than the second cylinder.

The second cylinder is taller than the first cylinder.

I wonder if you were able to use those important words to compare your cylinders.

Sam also thought of two more words that she could use.

I wonder if you thought about using these words too.

Sam said the first cylinder is larger than the second cylinder and the second cylinder is smaller than the first cylinder.

Sam was thinking about how much space each cylinder takes up so she could say which one was larger and which one was smaller.

I hope that you were able to compare your cylinders in lots of different ways, just like Sam.

On the second question, you needed to choose two cylinders that were similar.

These are the cylinders that Jacob chose.

He said, "I think A looks like a larger version of E.

"They are similar." Sam says, "I think C and F are similar, "because they are both short and wide." I wonder if you chose the same ones as Jacob or Sam or if you chose different cylinders.

Don't worry if you chose different ones, as long as you've done what Jacob and Sam have done and you've explained your reason why you think they are similar.

Then you needed to choose two cylinders that you thought were very different.

Jacob chose B and G.

He says, "B looks very different to G because B is smaller.

"It takes up less space." Sam said A and F are very different, because A is much taller and narrower.

Well done if you were able to think like Jacob and Sam and give a really good explanation for how your cylinders that you chose were very different.

Good work.

Now, it's time to have a look at the second part of this lesson.

You are going to start learning how you can compare different 3D shapes.

I wonder which 3D shapes we are going to be looking at.

Let's have a look now.

You know that when you compare shapes, you are looking carefully to see what is the same and what is different.

You had a look at these two shapes.

You'd be able to think about what is the same and what is different.

Jacob says, "I think one is narrower and one is wider." Sam says, "I think one is taller and one is shorter." The things that Jacob and Sam have noticed are based on the size of the shape.

There are other ways to compare shapes too.

Now, you are going to start learning how you can compare shapes based on their properties.

Jacob says, I remember that the properties of 3D shapes can be the faces, the vertices and the edges.

I wonder if you can remember what those words mean.

Have you learned about those things before? Let's have a look.

You could compare these shapes by looking at the faces.

Jacob could say that the cuboid has six rectangular faces and Sam could say that the cylinder has two circular faces and a curved surface.

Their faces are different, aren't they? They have a different number of faces and they have different shaped faces.

You could compare these shapes by looking at the vertices.

Jacob says that the cuboid has eight vertices and Sam says that the cylinder has no vertices, so their faces are different and their vertices are different too.

You could also compare these shapes by looking at the edges.

The cuboid has 12 edges.

The cylinder has no edges.

Their edges and their vertices and their faces are all different.

Let's compare the cuboid with another 3D shape.

I wonder what you could say this time about the faces, the edges and the vertices.

Let's have a look.

"They both have six faces," Jacob says.

That's true, isn't it? So, now there's something that's the same.

They both have six faces.

Sam says they both have eight vertices and 12 edges.

Ooh, these shapes have the same number of faces, the same number of vertices and the same number of edges.

I wonder if there is anything that's different.

Jacob says, "They're not the same shape.

"What is different?" Can you spot anything? Let's have a look.

Sam says that the cube has six square faces.

The cuboid does not.

The faces on the cuboid are rectangular, but they are not all square.

The cube has six square faces, so the shape of the face is different, but the number of faces is the same.

Let's check if you can spot who has compared these 3D shapes correctly.

Jacob says, "The cone and the cylinder both have one vertex." Sam says, "The cone and the cylinder both have a circular face." Who do you agree with? Pause the video and have a think.

Let's have a look.

Sam said, "The cone and the cylinder both have a circular face." If you look carefully at the shape, you can see here that that is correct.

They do both have a circular face.

Jacob said the cone and the cylinder both have one vertex.

If you look carefully at the shapes again, you can see that there is a vertex here, but that's it.

There aren't any other vertices.

That means Jacob is not correct.

The cone has one vertex, but the cylinder has no vertices.

Well done if you said that Sam was correct.

Good job.

Jacob has made a 3D shape from playdough.

What shape do you think that looks like? Jacob says, "My shape looks like a square-based pyramid." Sam has got a challenge for Jacob, a playdough challenge.

Are you ready to see what Sam's challenge is? She says, "Can you make your pyramid look like a cone?" Jacob's got to change his shape to try and make it look like a cone.

I wonder what he's going to do.

Let's have a look.

Jacob is going to try the challenge.

He is going to change his pyramid so that it looks like a cone.

He says, "I know that a cone has one vertex and one circular face." Jacob is visualising a cone.

That means he's getting a picture of a cone in his mind, so that he can work how to change his pyramid into a cone shape.

He knows it has one vertex and he knows it has one circular face.

He says, "I could make the square face of the pyramid "into the circular face." He's going to shape his playdough to make it a bit more round so that the base isn't shaped like a square anymore.

It's getting more into a circle shape.

Then he says, "I need to roll the triangular faces, "until they make a curved surface." He's going to roll his triangular faces and now he has made a curved surface.

Sam says, "You have made your pyramid look like a cone, well done." Jacob had to think really carefully, about what a cone looks like to be able to change his playdough.

He did really well at that, didn't he? Let's check if you can think, about how you might change a playdough shape.

This playdough is shaped like a triangular prism.

How might you be able to change it into a cylinder shape? Whose idea would you choose? Jacob says, "I think you could roll it "to create a curved surface" and Sam says, "I think you could squash it to make it flatter." Pause the video and see who do you agree with.

Let's have a look.

Jacob said, "I think you could roll it to create a curved surface." If you imagine rolling this shape, I wonder what would happen to it.

Let's have a look.

Jacob is correct.

If you rolled this triangular prism shape, it could change into a cylinder.

The rectangular faces around the middle, would become a curved surface and the triangular faces at the ends, could become circular faces.

What would happen if we tried out Sam's idea? She said, "I think you could squash it to make it flat." Is that going to help to make a cylinder shape? Let's have a look.

If you squashed this triangular prism shape, it wouldn't make a cylinder.

Sam is not correct.

If you squashed this triangular prism to make it flatter, it could change into a cuboid.

Where you squash the triangular prism, it could make an extra face and the faces could change shape to become rectangular, so it would end up looking like a cuboid.

Well done if you were able to visualise those shapes to have a picture in your mind and imagine how the playdough might change.

Now it's time for you to practise comparing different 3D shapes.

You are going to choose two shapes from the four that you can see here.

You are going to make a list of the things you can see that are the same and the things you can see that are different.

Try and think about the properties of the shape, the faces, the vertices and the edges.

When you finish that question, you are going to have a go at this second part, I would like you to make a shape like a cylinder from playdough.

Then you are going to try out Sam's challenge.

Let's have a look at the challenge that Sam has given you.

Sam's challenge this time is how can you change your cylinder to look like a cone? Before you change your playdough, try and describe to a partner how you could change it.

So, describe your ideas to your partner, before you change your playdough.

That will help you to visualise the shapes, make a picture in your mind.

When you finish describing your ideas to your partner.

Then try out your ideas on the playdough and see if it works.

Can you meet Sam's challenge? Can you change this cylinder shape into a cone shape? Jacob says, if you finish, maybe you could give a new playdough challenge to your partner.

You could be like, Sam, you could think of a new challenge for your partner and maybe they could think of a new challenge to give to you.

I'm sure you are really excited to go and try out Sam's challenge, so you are going to pause the video and go and do that piece of work now.

Off you go.

Well done for thinking so carefully.

Let's have a look and see how you got on.

On the first question, you needed to choose two shapes and make a list of things that are the same and things that are different.

I chose B and D.

If you didn't choose B and D.

Don't worry.

Look at the sort of things that I noticed and see if any of yours are similar to these.

I noticed that B and D are both prisms. They both have rectangular faces.

They both have more than eight vertices and more than 12 edges.

I described the faces, the vertices and the edges of these shapes.

I have compared the faces, the vertices, and the edges of the shapes that I chose.

I wonder if you did that too.

Here are the things I noticed that are different.

B has two pentagonal faces, but D has two hexagonal faces.

I compared the shape of the faces.

D has a greater number of faces, vertices and edges than B.

I've also compared the properties, haven't I? I've compared the number of faces, the number of vertices and the number of edges.

I hope that you remember to think about the properties of those shapes too when you were comparing them.

Now, let's have a look at the second part of this work.

Sam's challenge.

Remember, she wanted you to try and change your cylinder into a cone.

This is how you might have tried to complete Sam's challenge.

Jacob said, "I kept one circular face.

"I rolled the curved surface into a point "to look like a vertex." So, he kept one of the circular faces and he rolled the shape to make a vertex that was opposite the circular face.

I wonder if you did that too.

Did you manage to get your playdough to look a little bit like a cone? Well done if you did, that was quite a tricky challenge from Sam.

Then you might have given a playdough challenge to your partner or they might have given one to you.

Maybe you gave a challenge like this.

Jacob gave Sam a challenge to change a cuboid into a cube.

Sam made this shape to begin with, a shape that looks like a cuboid, and then she said I pushed the ends in towards the middle to create six square faces.

Sam remembered that a cube needs to have square faces, so she tried to push the ends in and make those faces into square shapes.

Well done if you were able to think about how you could change your playdough from one 3D shape into a different one.

Excellent work.

Now, that you are at the end of the lesson, you have learned that you can compare the size of 3D shapes, using words like wider, narrower, taller, shorter, larger and smaller.

You also know that you can compare 3D shapes by looking carefully at their properties.

This could include the number of faces, vertices and edges, and also the shape of the faces as well.

If you were comparing a cone with a cylinder, these are some of the things that you might notice.

You could say both shapes have a circular face.

Both shapes have a curved surface.

The cone has a vertex, but the cylinder does not.

The cylinder has two circular faces and the cone only has one.

You have worked really hard in this lesson today and thought really carefully, about how you can compare 3D shapes.

Very good work.

I hope that I will see you again soon for some more maths learning.

Bye.