Lesson video

Hello everybody.

My name is Mrs. Johnson.

I am so excited 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, Measure Length Using Centimetre Cubes.

It comes from the unit numbers zero to 20 in different contexts.

By the end of this lesson, you are going to be able to measure length using centimetre cubes.

Don't worry if you haven't heard of centimetre cubes before because I am going to help you, and we will be able to learn it together.

By the end of this lesson, you are going to be an expert on centimetre cubes.

You will know all about them.

There are some key words that I would like you to practise saying so that you are ready for this lesson today.

I will say them first, and then it will be your turn.

Ready? My turn, centimetre.

Your turn.

My turn, standard unit.

Your turn.

My turn, accurate.

Your turn.

Excellent, well done.

Listen out for those words in this lesson because they will really help you with your learning today.

There are going to be two parts to this lesson.

To begin with, you are going to learn about measuring accurately with cubes.

And then, in a little while, you are going to learn to describe length in centimetres.

Let's start by thinking about measuring accurately with cubes.

There are going to be two friends in this lesson who will help you.

Their names are Laura and Andeep.

Look out for them today, because they're going to show you something that is really important.

Let's get started.

Laura wants to use cubes to accurately measure the length of some of her toys.

Let's see what she does.

She's going to place her cubes along the car.

She's got, one, two, three, four, five, six.

The pink car is six cubes long.

Now, she wants to measure the van.

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

The orange van is seven cubes long.

Laura can also measure the height of the toys using cubes.

One, two.

The pink car is two cubes tall.

Let's see what happens with the van.

One, two, three, four.

The orange van is four cubes tall.

Have a look at how Laura placed her cubes to measure the car and the van.

How did Laura make sure that her measurements were accurate? Pause the video and talk to a partner, or have a think.

How did Laura make sure that her measurements were accurate? Well done for having a good think about that.

There are lots of different things that Laura has done.

You might have noticed that all her cubes are the same size.

Maybe you said that the cubes are in a straight line.

Did you notice that there are no gaps between the cubes? And you might have said that each line of cubes start and finish at the end of the toy.

Laura did all of those things to make sure that her measurements were as accurate as they could be.

Well done if you noticed those things too.

Andeep is going to do some measuring, but he's going to do it in a slightly different way.

Andeep is going to build a straight line of cubes first, and then he can place each object along the line to measure its length.

So here is Andeep's line of cubes.

He can place his car on the line, and Andeep can see that the car comes to this cube here.

So if we count the cubes up to that arrow, we can see one, two, three, four, five.

We can say, the orange car is five cubes long.

Now, let's try a different toy.

Let's try this green vehicle.

The end of the green vehicle comes to this cube.

Let's count them.

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

The green vehicle is six cubes long.

Now, Andeep has built a tower of cubes so that he can measure the height of each toy.

He's going to place his orange car next to the tower, and he can see that the top of the car comes here.

Ooh, the height of the car is not exactly lined up with one cube, it is between two cubes.

That means you could say the orange car is between one and two cubes tall.

Let's see what happens with the green vehicle.

Here is the top of the green vehicle.

It's not exactly lined up with one cube, it is between two cubes.

So this time you could say, the green vehicle is between two and three cubes tall.

You are going to go and do a little bit of accurate measuring with some cubes.

You are going to choose your own toys or objects that you have around you.

Maybe you've got some toy cars, like Laura and Andeep.

If you haven't, don't worry, you can measure anything that you can find around you.

Laura says, "Remember to be accurate, like I was." Place your cubes in a straight line, make sure that there are no gaps, and that you go all the way from one end of the object to the other end.

Andeep says, "Will you have any lengths that are between two cubes, like I did?" Ooh, I wonder if you will? When you have finished measuring all of your objects, I would like you to tell a partner your results, and I would like you to show your partner how you used your cubes to measure accurately.

Go and get your cubes and start measuring those objects.

Ready? Off you go.

Well done everybody, you have tried really hard to measure accurately.

Let's have a look at how you might have used your cubes to measure accurately.

You might have built a tower like this, and then placed your object next to it.

You might have thought about which cube the toy or the object comes up to, and then counted like this, one, two, three, four, five, six.

And you could have said that the teddy is six cubes tall.

You might have built a line of cubes this way, and then you could place your object along the line.

If you measured a playing card, like this, you could count the cubes, and we can see there are one, two, three, four, five.

You could say, that the game card is five cubes long.

You might have measured something a bit bigger, maybe something like this tablet.

If you look at how this tablet has been measured, it's been placed along the line.

But the end of the object is between two cubes.

This is just like what happened to Andeep, isn't it? So you would say, that the tablet is between nine and 10 cubes long because it doesn't exactly line up with where one of the cubes is.

I wonder if you found any measurements that were between two cubes? Did you remember to place your cubes in a straight line, with no gaps? Well done if you did, because that is how you measure accurately, good job.

Now, we are going to move onto the next part of the lesson, and you are going to learn how you can describe length in centimetres.

I wonder if you've ever heard that word, centimetres, before this lesson today? Think about where you might have heard it, or maybe, where you might have seen it.

Let's see if the next part of this lesson helps you to think about when you might have seen centimetres before.

Laura and Andeep decided to use their cubes to measure the same car.

Laura measured the car first.

She says there are one, two, three, four, five, six, so the car is six cubes long.

Then Andeep did the same thing.

One, two, three, four.

Andeep says, "No, the car is four cubes long." Hmm, Laura thinks it's six cubes long.

Andeep thinks it's four cubes long.

Laura says, "why are our results different? Did one of us forget to measure accurately?" Look at how Laura and Andeep have placed their cubes.

Do you think they have forgotten to be accurate? Hmm, let's see what Andeep says.

"I think we were both accurate." I agree with that.

They have measured accurately, haven't they? The cubes are in a straight line and there are no gaps.

Andeep says, "what has happened is that we have used different cubes, so we have different results." They are both correct, but they are not the same because they've used different sized cubes.

Laura says, I wonder if there is a way that we could make sure our results are the same.

I wonder if there's something that Laura and Andeep could use, that would make sure that they got the same result.

Let's look a little bit more into that.

When you choose your own objects to measure length, everyone might get different results because they have used different objects.

That's what has just happened, isn't it, to Laura and and Andeep.

They got different results because they chose different cubes.

This is called a centimetre cube.

Centimetre cubes are really special because they are always exactly the same size.

So these are all centimetre cubes.

Sometimes they might be different colours, but they are all the same size.

Laura and Andeep are now, going to measure this car using centimetre cubes.

Let's see what happens.

Laura says there are one, two, three, four, five, six, seven.

The car is seven centimetre cubes long.

Let's see what happens when Andeep uses centimetre cubes.

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

The car is seven centimetre cubes long.

Oh, they've both got the same result this time.

Their results are the same because they have both used centimetre cubes.

Centimetre cubes are known as a standard unit of measure because anybody who uses them accurately to measure the length of an object, will get the same result.

It doesn't matter who is using them or where they are using them.

If they are using centimetre cubes accurately to measure the same object, the result will always be the same.

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

If you want to measure the height of this astronaut using centimetre cubes, Laura could measure it and she would find it's one, two, three, four, five, five centimetre cubes tall.

And if Andeep did the same thing, he would find one, two, three, four, five.

The height of the astronaut is five centimetre cubes tall.

Laura says, "Our results are the same because we both used the standard unit of centimetre cubes." If you use a standard unit, your result will be the same.

A centimetre is a standard unit of measure because it does not get bigger or smaller, it will always be the same size.

Centimetres are used in different countries all around the world, and they are always the same size.

Laura says, "I found some things that are about the same size as a centimetre in length.

The width of a paperclip is about a centimetre.

The nail on your thumb is about a centimetre, and a ladybird is about a centimetre long.

When you use centimetre cubes to measure length, you can give your measurement in centimetres.

You don't have to say that you used cubes because centimetres are a standard unit of measure that people will already know about.

So you don't need to say, centimetre cubes, you can just say, centimetres.

So this astronaut is five centimetres tall.

This car is seven centimetres long.

Let's check if you can measure in centimetres.

This tower has been built out of centimetre cubes.

Who is correct? Laura says the toy panda is 10 centimetres tall.

Andeep says the toy panda is 11 centimetres tall.

Pause the video and see who you think is correct.

Let's have a look.

I bet you did some really good counting them.

First, you need to think about where the top of the panda is.

So I'm just going to place an arrow here, so we can see.

Then you need to count the cubes all the way up to that arrow so that we can see how many cubes there are.

That will tell us how tall the panda is.

Let's count them together, ready? One, two, three, four, five, six, seven, eight, nine, 10, there are 10 centimetre cubes, so that means that the panda is 10 centimetres tall.

Laura was correct.

Here's another check for you to try.

How tall is this robot? Who do you think is correct this time, Laura or Andeep? Pause the video and have a go.

Well done.

Again, let's find the top of the robot and place an arrow just here, and then let's count the cubes to check.

One, two, three, four, five, six, seven, eight, nine, there are nine centimetre cubes.

That means that Andeep is correct, the robot is nine centimetres tall.

Now, it is your turn to go and do a little bit more work.

You are going to have a look at these objects that have been placed next to a line of centimetre cubes.

Can you write the length of each object in centimetres? You're going to look at the pen, the pencil, the highlighter, the eraser, and the robot.

For each object, look really carefully at the centimetre cubes and then write the length.

Once you've done that, you have a second job to do.

On the second part of your work, you are going to choose your own objects to measure.

Perhaps you could use the same ones that you used last time, or you could go and find some new ones.

They could be toy cars or teddies or they could be things like pencils and pens.

You can choose what you would like to measure.

Use centimetre cubes to find out how many centimetres long each object is.

Laura's reminding you to remember to be accurate like she was.

Make sure your cubes are in a straight line, with no gaps, and that you go all the way from one end, to the other end of the object.

When you finished measuring, ask your partner to measure the same objects that you have, using centimetre cubes.

See if you notice anything about your results, and your partner's results.

Are you ready to go and use your centimetre cubes? Excellent, off you go.

Well done everybody.

Let's see how long each of these objects was, and you can see how you have got on with your work.

The orange pen is 14 centimetres long, and the pencil is 15 centimetres long.

The highlighter pen is 10 centimetres long, and the eraser is five centimetres long.

The robot is nine centimetres tall.

Well done, if you got those correct, that shows that you know how to use centimetre cubes to measure length accurately.

On the second part of your work, there are lots of different ways that you might have done this, but I'm going to show you a few examples.

This is how you might have used centimetre cubes to measure the length of some of your different objects accurately.

So first, I'm going to show you with this teddy.

You could build a tower of centimetre cubes next to the teddy, and then count the cubes to see how many centimetres tall the teddy is.

Ready? One, two, three, four, five, six, seven, eight, nine, 10, 11, the teddy is 11 centimetres tall.

Maybe you didn't measure how tall something was, maybe you measured how long something was like this, one, two, three, four, five, six, seven, eight, nine.

The game card is nine centimetres long.

When you finished measuring, did you talk to your partner and watch them measure the same objects? What did you notice about your results and their results? Andeep said, "When I watched my partner measure, I noticed that our results were the same." Did you notice that too? That when you and your partner both used centimetre cubes, your results were the same? I wonder why, did you think about that? Laura has remembered that the results are the same because you both used a standard unit, which was centimetre cubes.

Well done, if you talked about using a standard unit.

That shows that you are thinking really carefully about centimetre cubes and how to use them to measure length, well done.

Now that you are at the end of the lesson, you know that when you use cubes to measure length, you might get different results because the cubes might be different sizes.

You have learnt that centimetre cubes are special.

Centimetre cubes are a standard unit of measure because they are always the same size.

They allow everyone to get the same results.

If you use centimetre cubes to measure length, you can give your measurement in centimetres, you don't have to say cubes.

For example, this highlighter is 10 centimetres long, and this toy car is seven centimetres long.

Well done, for all your really careful thinking today and your hard work.

You have done an excellent job.

I hope I'll see you again soon for some more maths learning.

Bye everyone.