Lesson video

Hi, everyone.

Thank you so much for joining me.

My name is Miss Jeremy, and today's math lesson is all about 3-D shapes.

We're going to be using and applying our knowledge of the properties of 3-D shapes, so find yourself a nice, quiet space, and get ready for your learning, and once you're ready, press Play to begin your lesson.

Let's begin by looking at our lesson agenda for today.

We're going to start with a warm-up where we'll be naming some 3-D shapes that you might have seen before.

We'll then look at describing 3-D shapes before looking at the properties of them as well, and we'll apply our knowledge of this at the end of the lesson before our independent task and quiz.

For today's lesson, all you'll need is a pencil and some paper, so pause the video now to get these resources and find yourself a nice, quiet space for your learning, and then press Play when you're ready to begin the lesson.

So let's begin with our warm-up, which is all about naming 3-D shapes.

On the board here, you can see there's a series of six shapes and six matching names, and our task is to match up the shapes to their names, so as you can see, these are just representations of 3-D shapes.

I don't actually have the 3-D shapes here, and they are kind of flat on the screen, but they are representations of 3-D shapes with the dotted lines demonstrating how the shape is 3-D rather than 2-D.

3-D stands for three-dimensional, so let's think about which of these words match to their correct shape.

If you'd like to, pause the video now and spend a bit of time seeing whether you can match any of these shape names to their corresponding 3-D shapes, and resume the video once you're ready, and we'll have a look at this together, so let's have a little peek, and let's see the ones that, perhaps, are fairly obvious for us, so the first one is a cube, and you can see that a cube is special because it has faces that are all squares, so each of those faces is exactly the same in terms of its length and in terms of its width, and they are all squares, and they form a cube.

The next one is a bit like a cube, but instead of using squares as the faces, rectangles are used.

Sometimes this shape also has some squares within it as well, and this is called a cuboid, so you can see the name is very similar to the name cube, but it's called a cuboid where rectangles are used instead of squares.

The next one might remind you of something that you have during the summer, so sometimes in the summer you might go to a van and get something that's filled with delicious ice cream, and we call this a cone, and you might remember that because it looks a little bit like an ice cream cone.

In this case, it's an upside-down ice cream cone, and so this is called, in 3-D mathematical terminology it's called a cone.

The next one is a triangular prism, so it uses two faces, which are triangles, and the other three faces are rectangles.

It's like an elongated version of a pyramid, so we call this a triangular prism.

It's a prism.

The next one is something that you might recognise if you've ever had tins in your house, if you've had tins of baked beans or soup in your cupboard, and this shape here is called a cylinder.

It is made up of two faces, which are flat and circular, and then one curved face that goes all the way around the outside, and the final one is a square-based pyramid.

Now, a square-based pyramid has different faces.

It's got four triangular faces all the way around the outside, and then its base is made of a square.

There are other types of pyramids that you can get as well.

Another one is called a triangular-based prism or triangle-based prism.

Sometimes these are called tetrahedrons as well, so you can see here we've got a series of shapes, and we've matched them to their correct names.

If you need to spend a bit of time memorising these names and these shapes, pause the video now, and then resume it once you feel confident with them.

Let's focus in on one of these shapes in a little bit more detail.

On the screen here, I've got two different representations of shapes.

I'm going to call them shape a and shape b.

What I'd like you to do, before I explain anything about these shapes, is to tell me what you notice.

What do you notice is the same about these shapes? What do you notice is different? And what would you call these shapes if you needed to describe them? I'm going to give you 10 seconds to see if you can answer those questions.

What is the same? What is different? What would you call these shapes? Okay, looking at this together then, so the main difference between shape a and shape b is that shape a is a 3-D shape, whereas shape b is a 2-D shape.

3-D stands for three-dimensional.

Your turn.

Three-dimensional, and 2-D stands for two-dimensional.

Two-dimensional.

3-D shapes have three dimensions that we use to measure them.

We have the length, the width, and the depth of the shape, whereas 2-D shapes only have two dimensions that we use, which is the length and the width.

3-D shapes, like the one on your left there, shape a, don't sit flat on a piece of paper.

We can draw them out flat, but they are shapes that stand up and are not flat shapes, whereas shape b is a two-dimensional shape that can be drawn flat on a piece of paper.

Shape a is what we would call a cube.

This is how we write it, whereas shape b is called a square.

However, they are similar in some ways because shape a is actually made up of lots of different versions of shape b.

A cube is made up of lots of squares.

You can see that the faces of a cube are all square.

I've got a dice here to show you an example, so this dice is a cube.

It's got slightly curved corners here, but essentially, this is a cube, and it has faces that are all squares.

We have, in total, one, two, three, four, five, six faces, and all of those faces are square, so the similarities between these shapes is that actually, whilst one is 3-D, and one is 2-D, one of them, shape a, is made up of shape b, so the cube is made up of six faces, which are all, so let's look at this terminology in a little bit more detail.

We've already spoken about what a face is.

A face is a flat or curved surface of a 3-D shape, so reminding again that if we've got a dice, we've got some flat surfaces on this dice, and that would be called a face, one of those.

If you think about another shape, for example, I've got my candle pot here, which is a cylinder, we have got a flat surface at the bottom there, which is a flat circular surface, but this surface across here is curved, so you can either have a flat face, or a curved face, or both of those types of face within a three-dimensional shape.

Now, an edge is slightly different.

An edge is the area where two of the faces on your 3-D shape meet, so you can see here that this is the edge, one of the edges on my cube.

It's where this face and this face meet together.

That is called an edge.

When we talk about a side, we're referring to a 2-D shape, so when I look at my square, this is one of the sides of the square.

That's a two-dimensional term that we use to describe either the length or the width of a 2-D shape, and a vertex is a corner, so a vertex is where two or more line segments meet and form a corner.

You can see that is a vertex there.

That is also a vertex there.

That is also a vertex there.

One of these corners is called a vertex.

Lots of them, the plural of vertex, is vertices, so we would write it like this, vertices.

You can also, in some shapes, for example, in a cone, have an apex.

An apex is a form of vertex, and an apex is the very top vertex on your shape.

It is usually opposite the base of your shape.

It's the one at the very, very top, but in a cube, because we can turn a cube any way around, and it doesn't have a specific base, we have just vertices.

We don't have a specific apex, so I'd like you to practise using these terms to describe these shapes.

First of all, let's work out what the names of these shapes are.

We saw some of these earlier on in the lesson.

Can you remember what we would call these three shapes? I'm going to give you five seconds.

So you might remember that this is called a cylinder.

It's a bit like the candle pot that I showed you earlier.

This one is called a square-based pyramid, and that's because it's a pyramid, but it has a square face on its base, and this is called a sphere.

Can you use some of these terms, face, edge, side, or vertex, to describe these 3-D shapes? You might not need to use all of those words, but can you use some of them to describe these 3-D shapes? Pause the video now to complete your task and resume it once you're finished.

So how did you get on? Let's have a look at, maybe, one of these shapes together.

Let's look at our square-based pyramid, so I can see, in terms of the faces of the square-based pyramid, we have five faces in total.

Four of those faces are triangular.

They're triangles.

You can see there's one.

We've got another one there, two.

We've got one at the back there, three, and one just on the right here, four.

There are four triangles to make up some of those faces, and the base of the pyramid is a square.

Looks a little bit rectangular there, but it is a square-based pyramid, so it is a square, so you can see that we have five faces on our square-based pyramid.

In terms of the edges, let's count them as we go, so we've got one, two, three, four, five, six, seven, eight, eight edges on our square-based pyramid, so in terms of the number of faces and the number of edges, we can see really clearly, just with that two-dimensional representation, the number of faces and the number of edges, and in terms of vertices, well, let's count those.

We've got one, two, three, four, five.

We've got five vertices, with this one here being the apex.

This is at the very top, and you can see it's directly opposite the base of the pyramid, so let's apply our knowledge of some of the 3-D shapes we've been learning about.

While out shopping, I bought items that use these 3-D shapes.

What could the items have been? So we've got cuboid, cone, cylinder, cube, sphere, and triangular prism.

I want you to think about the last time you went to the supermarket or to your local shop.

Did you see any of these shapes whilst you were shopping? I'm going to do a few for you, and then I'm going to ask you to think about a few as well, so we've already spoken about the fact that if you have some ice cream in the summer, you might eat out of an ice cream cone, and that uses a cone shape, so I'm going to write ice cream cone here.

Let's think about, now, what might use a cube shape.

Can you think of an item that you might buy in the shop that has a cube? Well, for me, when I went shopping recently, I bought a delicious box of chocolates, and it was shaped in the shape of a cube, so I'm going to write box of chocolates here, so now it's your turn.

Can you think of any of the other items that you might buy in a supermarket that have these shapes? Pause the video now to have a little think, and then resume it once you're ready.

Okay, how did you get on? Did you manage to find a matching item for each of those different 3-D shapes? If you found that a little bit challenging, go back and have a look at our matching up of all of those different 3-D shapes to the different names, so you know exactly what they look like.

The next challenge for us to apply our 3-D understanding to is this.

As you can see on our screen, we have three two-dimensional shapes, and when looking down at some 3-D shapes, this is what I see.

I see these 2-D shapes in front of me.

What could the corresponding 3-D shapes be? So if you were looking directly down at a shape for a, b, and c, and you knew it was a 3-D shape you were looking down at, what could those shapes be? I'm going to give you 10 seconds to see if you can work out what those shapes might be.

Okay, so there's a couple of different examples or a couple of different answers for each of these examples.

However, let's look at what they might be, so if you're looking directly down at a square, which is shape a, the chances are, you're probably looking at a cube because a cube has faces which are square.

You might potentially be looking at a square-based pyramid that has been flipped upside down, so you're looking at the base.

That's a potential as well.

You might also be looking at a cuboid, but looking at one of the smaller sides, one of the smaller faces, sorry, that uses a square because a cuboid has to have some rectangles within it as well, but the likelihood is if you're looking down and you're seeing a square, you're probably seeing a cube.

For shape b, if you're looking down and seeing a circle, the chances are that you might be seeing a cylinder.

Thinking back to my candle holder, my candle pot, remember the base of my candle holder has a circle as one of its faces, so it could be that you're looking down at a cylinder.

A sphere is a shape that is totally round, a bit like a globe.

You might've seen a globe before, or a circular light.

That is something that also uses a circular face.

It's not directly a circle, however, so it depends.

If you're seeing exactly a circle, it's likely that you're looking at something like a cylinder in this case, and for shape c, chances are, if you're looking down at a rectangle, you are looking at a cuboid, which makes use of rectangular faces, so in this case, the chances are you're probably looking at a cuboid.

You may be looking at a prism of some kind, so if you were looking at a triangular prism, and you were looking at one of the rectangular sides, this could also be a triangular prism, but we'll select cuboid, as that's perhaps the most obvious, or the first answer that you might have come up with there.

Moving on to your independent task for today.

You've got two different challenges to complete.

On the left there, you've got some riddles.

Each riddle describes one of the shapes that we've been talking about today and asks you to determine what the shape is based on its properties.

For the second task, you have got a series of different three-dimensional shapes that we've seen today already, and I want you to think about how these shapes could be sorted into two different groups.

I'll give you one example.

For example, some of these shapes make use of rectangles as one of their faces, so here, I can see a cuboid uses rectangles as at least one of their faces, and we've got the triangular prism that uses rectangles as some of the faces as well, whereas these shapes do not use rectangles within their three-dimensional shapes as any of their faces, so we might break this up into shapes that use rectangles, which is the second circle here, and shapes that do not use rectangles as one of their faces.

That's one way of dividing these into groups.

Can you think of other ways to divide these 3-D shapes into two different groups based on their properties? Pause the video to complete your task, and then resume it once you're finished.

Okay, so how did you get on? As you can see on the screen, we've got the answers for riddles 1 to 4 there.

Triangular prism was number 1.

A cone was 2, cylinder for 3, and cuboid for 4, and how did you divide up those groups? Did you divide them in a similar way to me in terms of the number of faces? Did you look at the vertices? What were your two groups? Another group you might have had was shapes that have curved bases, like the cylinder and the cone, and shapes that only have flat faces, like the cuboid, the square-based pyramid, and the triangular prism.

It's the end of the lesson now, but if you'd like to, please ask your parent or carer to share your work on Twitter, tagging @OakNational and #LearnwithOak.

It'd be really lovely to see what you decided to group those 3-D shapes into.

Now it's time to complete the quiz.

Thank you so much for joining us for a lesson today.

It's been really great to have you.

Do join us again soon.

Bye-bye.