Lesson video

In progress...


Hi there.

My name is Miss Darwish, and for today's math lesson, we are going to be converting units of length.

But before we get started with the lesson, if I could just ask you to take yourself away from any distractions, so you're ready for the lesson.

So our agenda for today is first of all, we're going to be looking at the relationship between millimetres and centimetres.

And then we're going to be looking at the relationship between centimetres and metres, and then metres and kilometres.

And then at the end of the session, as always, there will be a quiz for you to do on today's learning.

So for this lesson, you will need a pencil, a sheet of paper or notebook, and a ruler.

So if you want to grab those things and we can start.


So, what would I use to measure the Eiffel Tower and an ant? Tell me.

Or a bug.


Would I use a ruler to measure the Eiffel Tower? Definitely not.

I've only got a 20 centimetre ruler over here, but even if it was a 30 centimetre ruler, definitely would not be any good for the Eiffel Tower.

What about a bug or an ant? Would this ruler be okay? Yeah.

My bug or my ant will not be bigger than this ruler.

Because if it is bigger than this ruler, I'd be scared of it, to be honest.

But anyway.



We're going to be talking about millimetres and centimetres, first of all.

So if you want to grab your ruler and just have a look at the little markings and see.

So in front of you, I've put, one centimetre is equal to 10 millimetres.

So one centimetre is equivalent, or the same, as 10 millimetres.

So I want you to see where one centimetres is on your ruler.

Which you can see on mine.

And I want you to count those little lines and see, are there 10? So there are 10 millimetres in one centimetre.

Okay, what about three centimetres then? In three centimetres, how many millimetres are there? Tell me.

30 millimetres, well done.


What about 70 millimetres this time? In 70 millimetres, what's that the same as in centimetres? If I have 70 millimetres, or I measure something that's 70 millimetres, how many centimetres is that? Seven centimetres, and you can see that on my ruler as well.

So in every one centimetre, there are 10 millimetres, or 10 millimetres in one centimetre.


What could I measure in millimetres? What could be measured in millimetres? I want you, I'm going to give you 20 seconds to look around the room you're sat in and find something that is small enough that could be measured in millimetres.

Go and grab me that item and come back and I'm going to do the same.


So I've got, first of all, my pen lid, okay? My purple pen.

The lid could be measured using in millimetres, okay? But I'm not going to get my pet giraffe and measure that millimetres, am I? Definitely not.

My pen lid, yeah.

My sponge, my little beauty makeup sponge as well.

I could measure that in millimetres as well, it's quite small.

What have you got? What did you find around your house that could be measured in millimetres? Okay.

So we've got the length of a bug.

Now, let's move on and talk about centimetres and metres, okay? So in one metre, there are 100 centimetres.


So 'cent', 'centi', 100 metres.

Think of it as century is 100, 'cent' usually means 100.

So 100 centimetres make up one metre.

Okay, what about 350 centimetres? How many metres? Have a think and then tell me.

How many metres is equivalent to 350 centimetres? Three and a half metres, of course.

So if we're saying one metre is equivalent to 100 centimetres, so if I have three metre sticks, for example, that would be 300 centimetres.

And then I'd have to have half a metre stick to give me the 50 centimetres.

So 350 centimetres is the same as saying 3.

5 metres.


What could I measure using metres? Again, I'll wait to have a look around the room you're in, around the house, and then come back.

I'll give you 20 seconds, go.

Something that could be measured in metres.


Tell me, what did you find? Or is it too big? Hopefully nothing too big.


I didn't go anywhere because I am that thing that could be measured using metres.

Okay? Our height, the person's height, the height of me, the height of you.

We measure our height in metres, right? Okay.

Do you know how tall you are in metres? If you're not sure, find out straight after this lesson, okay? Now, let's move on to talk about metres and kilometres.

So first of all, we were talking about millimetres to centimetres and then centimetres to metres, and now metres to kilometres.

Now kilo, can you say the word 'kilo' for me? What does 'kilo' mean? So there are 1000 metres in one kilometre, but what does 'kilo' mean? It means 1000.

What does it mean? 1000, well done if you said 1000.

So 'kilo' means 1000 and that's how I remember 1000 metres in one kilometre.

So there are a thousand metres in one kilometre.


Now, before we had a metre stick to measure metres, we've had a ruler to measure centimetres and millimetres.

And now what would we use for, to measure kilometres? So the next time you get into your parent or your carer's car, you can have a look at seeing the speed when they're driving.

It would be measured in kilometres.


Now, let's have a look at converting between units of length.

So it is 32,000 metres between my house and my friend's house.

32,000 metres between my house and my friend's house.

So we know that one kilometre is equal to.

1000 metres, well done.

So how many kilometres away is my friend's house is what I want to know? I know how far it is in metres, but how many kilometres away is it? I want you to have a think, write it down.


And hopefully you said 32 kilometres.

Well done if you did.

32,000 divided by 1000 is equal to 32 kilometres.

Okay, well done.

Now, I've got some converting activities for you to do.

So what I'd like you to do is you have got to.

let me just move myself out of the way there.

You've got to arrange the measurements below from shortest to longest and predict what they might be measurements of.

That means, guess what these might be measurements of, okay? And then come back and we can go through the answers together.

Good luck.

Okay, welcome back, hopefully you found that okay.

Should we go through the answers together now? Okay.

So, we needed to arrange the measurements from shortest to longest.

Let me just move myself out of the way.

There we go, that's better.


So we needed to arrange the measurements from shortest to longest, so you should have had 35 millimetres as the shortest.

And what did you predict that could be? Maybe your little finger, your pinky could be 35 millimetres.

Maybe the length of a butterfly, or a small bug could be 35 millimetres.


Maybe you had any other different ideas to me.

Okay, next we had.


5 metres, which maybe could be your height? I mean, a child's height could be 1.

5 metres, 150 metres.

I know my height is.

I am 165 centimetres tall.

Not very tall.

165 centimetres or one metre, 1.


So 1.

5 metres and then 160 centimetres, both of these could be the height of a person.

So well done if you've got these in the right order so far.

And then we've got 3,000 centimetres, which is how many metres? 3000 centimetres is about 30 metres.

That's quite tall.

So imagine 30 metre sticks.

So that could be the height of a monument or a statue.

Again, I'd love to know what your ideas were.

Maybe you had something different, different ideas to me.


And then, oop, move myself out of the way again, I'm always in the way.

And then 12 kilometres could be the distance from your house to.

and that's something you can investigate for me.

So you might want to ask your parents and work out on an investigation depending on where you live in the U.


, and work out, which area is roughly 12 kilometres away from you? Okay.

Well done.

Now, if you would like to share your work with Oak National, then please ask your parent or your carer to do so.

And so go on to Twitter, tagging @OakNational and to use the hashtag #LearnWithOak.

Now, I just wanted to say, well done on all the brilliant learning that you have done today, and good luck on completing the quiz.