Lesson video

Hello there.

My name is Mr. Tilston.

I'm a teacher and I feel very lucky because I get to spend this maths lesson with you.

Today's lesson is all about unit conversions.

Unit conversions are everywhere.

You just have to go to a supermarket and you'll see grammes, kilogrammes, litres, millilitres.

So it's good to know what they are and how to convert from one to the other.

And that's what we're going to do today.

So if you're ready, I'm ready.

Let's begin.

The outcome of today's lesson is, I can apply known unit conversions to convert from larger to smaller units of measure.

So for example, from kilogrammes to grammes or litres to millilitres.

We've got some keywords today.

We're going to look at these in a my turn, your turn style.

So my turn, equivalent.

Your turn.

My turn, convert.

Your turn.

Now I'm going to bet you've heard some of those words before, if not both of them.

However, you might be a little bit unsure about the meanings.

So let's have a look, because they're important words that are going to come up a lot today.

If two or more things have the same value, they are equivalent.

And convert means to change a value or expression from one form to the other.

So in the example that I gave a few seconds ago, it might be to change from litres to millilitres, for example.

That's converting.

Our lesson today is split into three parts or three cycles.

The first will be kilogrammes to grammes, then we'll look at kilometres to metres, and then litres to millilitres and metres to millimetres.

But if you're ready, let's begin by looking at kilogrammes to grammes.

In this lesson, you're going to meet Izzy and Lucas.

Have you met them before? They're here today to give us a helping hand with our maths.

So here's a bag of sugar.

You've seen something like this before, I'm quite sure.

Sugar is often sold in one kilogramme, and that's how you can write one kilogramme in its abbreviated form, one kg, bags.

Can you see it there? Look, one kilogramme.

So we've got a recipe here for muffins, and you might spot that it mentions sugar on there.

It gives a recipe quantity of sugar in grammes.

So the bag of sugar is sold in kilogrammes, but the recipe requires grammes.

So the question is, the first question, does the recipe require less than a bag of sugar or more? Hmm.

We need to do a little conversion, I think.

The prefix kilo means 1,000.

So one kilogramme is equal to 1,000 grammes.

That's a really important fact, and that's going to come up again and again over the next sequence of lessons.

So see if you can have that one memorised.

One kilogramme is equal to 1,000 grammes.

And we might write that like that.

We'd read it in the same way though.

One kilogramme is equivalent to 1,000 grammes.

So the 250 grammes of sugar is less than a one kilogramme bag of sugar.

Because 250 is less than a thousand.

Lucas is exploring the relationship between kilogrammes and grammes by writing one kilogramme on one side of a two-colored counter.

You might have some of these in your classroom, by the way, so you might be able to do the same thing if your teacher gives you permission.

So here we go.

So he's written that one kilogramme on one side of a counter, and he's written 1,000 grammes on the other side.

So imagine flipping that counter over and he's written 1,000 grammes on the other side.

And he does this lots of times.

And again, you might want to do that yourself if you can.

So he's done the same thing again.

So to represent another bag of sugar, one kilogramme bag of sugar, he's written one kilogramme on one side of the counter and then 1,000 grammes on the other side of the same counter.

And again and again and again and again and again.

So he's got lots of these counters where the red side says one kilogramme and the yellow side says 1,000 grammes.

And they're equivalent to each other.

They're the same thing.

Lucas is using his counters to help convert from different numbers of kilogrammes to grammes, using this stem sentence.

If one kilogramme equals 1,000 grammes, m kilogrammes equals m grammes.

Will you read that with me? Let's do it again.

If one kilogramme equals 1,000 grammes, m kilogrammes equals m grammes.

Now can just you read it, please, on your own? Ready? Go.

So let's have a look at this and let's use this stem sentence.

How could we fill it in? Let's have a look.

Well, if one kilogramme equals 1,000 grammes, two kilogrammes equals 2,000 grammes.

And you can see both of those values there.

The red side's showing two kilogrammes.

The yellow side is showing 2,000 grammes.

And they're equivalent.

They're worth exactly the same.

That would be like two bags of sugar.

Let's do another one.

See if you can fill this one in without my help.

What's this going to be this time, do you think? Let's have a go.

So if one kilogramme equals 1,000 grammes, three kilogrammes equals 3,000 grammes.

Pretty simple, don't you think? Let's do another one.

If one kilogramme equals 1,000 grammes, how are we going to complete this one? Four kilogrammes equals 4,000 grammes.

Another one.

See if you can do it first.

How many kilogrammes have we got? How many grammes have we got? They're equivalent.

They're the same.

Ready? If one kilogramme equals 1,000 grammes, five kilogrammes equals 5,000 grammes.

Can you see the pattern? Let's do it again.

Ready? Let's go.

If one kilogramme equals 1,000 grammes, six kilogrammes equals 6,000 grammes.

One more.

Last one.

You can do this now.

I bet you're really confident.

Do it before I do it.

Ready? Let's go.

If one kilogramme equals 1,000 grammes, how many kilogrammes have we got? Seven kilogrammes equals how many grammes? 7,000 grammes.

This would be equivalent to seven bags of sugar.

So you could say that seven bags of sugar weigh seven kilogrammes.

Or you could say they weigh 7,000 grammes.

It's the same thing.

So you're going to use that same stem sentence to convert the kilogrammes into grammes, okay? Have a look at the image.

Look how many kilogrammes you've got.

Can you convert that to grammes? Pause the video and give that a go.

How did you get on with that? Did you manage to do that stem sentence? Maybe you got the chance to practise it a couple of times because practise makes perfect.

Well, let's have a look.

So if one kilogramme equals 1,000 grammes, nine kilogrammes, that's what we can see there, equals? How many grammes is that? 9,000 grammes.

Very well done if you got that.

You're on track.

It's time for some independent practise.

Let's put those skills into action.

So question one, convert the kilogrammes to grammes.

And question two, that's a one kilogramme mass.

What would be the mass of six of those weights in grammes? So you convert it from kilogrammes to grammes.

And number three, we've got some weighing scales.

Convert the mass shown on the scale into grammes.

So look what it's pointing to in kilogrammes.

What would that be equivalent to in grammes? Number four, Lucas has bought some bags of rice.

Each one weighs one kilogramme.

He says, my rice weighs 7,300 grammes.

Is that possible? Explain.

So remember he's got full bags of rice.

And then a little question to ponder.

Would you rather have six kilogrammes of gold or 600 grammes of gold? If you were offered one of those, which would you take? And explain it.

Okay, well, give that a go and I'll see you soon for some feedback.

Welcome back.

How did you get on? Let's have a look.

Let's give you some answers.

So converting this from kilogrammes to grammes, well, I can see 3, 6, 8.

I can see eight kilogrammes.

Eight kilogrammes equals or is equivalent to 8,000 grammes.

And then that's a one kilogramme mass.

What would be the mass of six of them? That's six kilogrammes, and that's 6,000 grammes.

Convert the mass shown on the scale into grammes.

Well, I can see two kilogrammes.

Can you? So what's that in grammes? Two kilogrammes equals 2,000 grammes.

And Lucas has bought some bags of rice.

A bit like the bags of sugar, isn't it? They weigh the same.

Each one weighs one kilogramme.

He says, my rice weighs 7,300 grammes.

Is that possible? Explain.

No, that's not possible.

Whole numbers of kilogrammes are multiples of a thousand.

So you can have 1,000 grammes, 2,000 grammes, 3,000 grammes, 4,000 grammes, et cetera, et cetera.

You could have 7,000 grammes.

That's quite close to it.

You could have 8,000 grammes.

That's close to it.

But you couldn't have 7,300 because that's a multiple of a hundred but not a multiple of a thousand.

So look for those three zeros in the whole number will tell you it's a multiple of a thousand.

And then would you rather have six kilogrammes of gold or 600 grammes of gold? I know what I'd rather have.

There are 1,000 grammes in a kilogramme.

So you might have said you'd rather have six kilogrammes of gold because it's equivalent to 6,000 grammes.

So the value is actually 10 times greater than 600 grammes.

Well done if you said that.

Are you ready for cycle two? I think you are.

You're doing really, really well.

So cycle two, we're going to look at kilometres to metres.

Every Saturday morning, Izzy does a five-kilometer park run.

And so do I, by the way.

Every Saturday morning, nine o'clock.

It's possible to express that in metres.

You already know that the prefixed kilo means 1,000.

Can you remember that from the first cycle? So how far do you think one kilometre? And that's how you can write that in its abbreviated form.

How far is that? What do you think? One kilometre is equivalent to 1,000 metres.

So kilogramme, 1,000 grammes.

Kilometre, 1,000 metres.

They've got something in common, those words.

That's a really important fact that's going to come up again and again over the next few lessons.

So have that one memorised.

Have it locked and loaded.

One kilometre is equivalent to 1,000 metres.

And there we are in its abbreviated form.

We'd still read it the same though.

One kilometre equals 1,000 metres.

Let's investigate how far Izzy runs in metres, using conversion skills.

Let's convert from kilometres to metres.

Now, just like before, she's using counters to help convert from different numbers of kilometres to metres using the stem sentence.

If one kilometre equals 1,000 metres, m kilometres equals m metres.

Now again, will you read that with me please? Are you ready? Let's go.

If one kilometre equals 1,000 metres, m kilometres equals m metres.

Now just you read it.

Off you go.

So let's have a look.

Let's investigate.

What have we got here? It's a bit like before, isn't it? Does this ring a bell? If one kilometre equals 1,000 metres, two kilometres equals 2,000 metres.

This is pretty straightforward, isn't it, I think.

Right, what about this one? If one kilometre equals 1,000 metres, three kilometres equals 3,000 metres.

What do you think is going to come up next? This.

Ready? Let's go.

If one kilometre equals 1,000 metres, four kilometres equals 4,000 metres.

Let's keep going.

If one kilometre equals 1,000 metres, how many have we got now? Five kilometres equals 5,000 metres.

If one kilometre equals 1,000 metres, six kilometres equals 6,000 metres.

One last one.

If one kilometre equals 1,000 metres, seven kilometres equals 7,000 metres.

So this is how far she runs on a Saturday morning.

She runs five kilometres, and we could see that from the red counters.

Or looking at it from the yellow side, we could say she runs 5,000 metres.

They're the same thing.

They're equivalent.

The conversion can be shown on a number line.

So you can see a double number line.

We could call this a conversion number line.

Say the stem sentence each time.

So it's the same one as before.

If one kilometre equals 1,000 metres, m kilometres equals m metres.

We've got that one.

What about this one? If one kilometres equals 1,000 metres, two kilometres equals 2,000 metres.

If one kilometre equals 1,000 metres, three kilometres equals 3,000 metres.

If one kilometre equals 1,000 metres, et cetera, et cetera.

See if you can continue completing the stem sentence by yourself.

Let's do a check.

Izzy walks 10 kilometres for charity.

Is this more or less than 9,000 metres? Explain.

Pause the video, and have a go at explaining that to your partner if you've got one with you.

What do you think? Is that more or less? It's more.

There are 1,000 metres in a kilometre.

So there are 10,000 metres in 10 kilometres.

10,000 is 1,000 more than 9,000.

Well done if you said that.

Time for some more practise.

Two questions in this cycle.

Number one.

Fill in the blanks on the conversion number line.

So just like we did before, can you fill in the blanks? Kilometres on the bottom, look, metres on the top.

And then number two, convert the kilometres into metres.

They're a bit jumbly.

They're a bit jumbled up.

Doesn't matter though.

Count them and convert them to metres.

Pause the video.

I don't think will take you very long.

I'll see you soon.

Welcome back.

Let's have a look.

So the conversion number line goes like this.

One kilometre, 1,000 metres.

Two kilometres, 2,000 metres.

Three kilometres, 3,000 metres.

Four kilometres, 4,000 metres.

Five kilometres, 5,000 metres.

Six kilometres, 6,000 metres.

Seven kilometres, 7,000 metres.

Eight kilometres, 8,000 metres.

Nine kilometres, 9,000 metres.

And 10 kilometres, 10,000 metres.

And then number two, convert the kilometres to metres.

Well, there's six of them.

That's 6,000 metres.

Six kilometres is equivalent to 6,000 metres.

Well done if you got those.

Are we ready for the final cycle? I think so.

This is litres to millilitres, and metres to millimetres.

And you might notice the words millilitres and millimetres sound quite similar.

They've got something in common.

They've got a prefix in common in fact.

Let's investigate that.

So the prefix kilo tells you that a kilogramme is 1,000 grammes and the kilometre is 1,000 metres.

That's things we've explored so far today.

But not all unit conversions relating to 1,000 parts, which those two are, follow that rule.

So we've got different starters.

So one litre is equivalent to 1,000 millilitres.

So it's got that same relationship, 1,000 parts, but it doesn't start with kilo.

And we can write that like this.

We can abbreviate litre down to L and millilitres down to ml, which is good because they're quite long words.

That means it takes less time to write.

So that's one litre.

We can see one litre in this jug.

And we could also say that's 1,000 millilitres.

And once again, this is a fact.

That's a key fact that's going to come up lots.

So make sure that you've memorised that.

You might want to write it down if you don't think you'd remember it, but it's really important.

Now the prefix milli, so when you see milli at the start of a word, means one thousandth.

So it's a fraction, one thousandth.

And I'm pretty confident you've got some experience of thousandths.

I think you've probably done some this year.

Probably recently, in fact.

So a millilitre is one thousandth of a litre.

That's where we get the name from.

That's why it's a thousandth.

So let's have a look.

So again, the prefix milli means one thousandth.

So a millimetre is one thousandth of a metre.

So that's a metre stick.

You've probably got one of those in your classroom.

It probably looks quite familiar.

One metre equals 1,000 millimetres.

Now you're probably quite comfortable knowing that one metre equals a hundred centimetres.

Very good.

That is a unit conversion.

But today, we're looking at the fact that you can convert one metre into 1,000 millimetres.

Millimetres are such a small unit that we would have to zoom in to see them on this particular image.

So Izzy's drawing circles this time.

So not counters, but circles.

But as you can see, it's a very similar concept.

She's drawing circles.

That's something you can do even if you don't have counters.

Drawing circles to help convert from different numbers of litres to millilitres using the stem sentence.

And this stem sentence will look familiar to you.

If one litre equals 1,000 millilitres, m litres equals m millilitres.

Can we say that together please? Let's go.

If one litre equals 1,000 millilitres, m litres equals m millilitres.

Right, just you.

Off you go.

Very good.

Let's practise that.

What we've got here then? If one litre equals 1,000 millilitres, two litres equals 2,000 millilitres.

Does this look familiar? I think you're probably getting really good at this now.

If one litre equals 1,000 millilitres, three litres equals 3,000 millilitres.

If one litre equals 1,000 millilitres, four litres equals 4,000 millilitres.

Let's keep going.

If one litre equals 1,000 millilitres, five litres equals 5,000 millilitres.

If one litre equals 1,000 millilitres, six litres equals 6,000 millilitres.

What do you think is coming up next? If one litre equals 1,000 millilitres, seven litres equals 7,000 millimetres.

Pretty straightforward.

It follows a pattern.

The conversion between metres and millimetres can be shown on a number line, just like before, a double number line, a conversion line.

Say the stem sentence each time.

So if one metre equals 1,000 millimetres, m metres equals m millimetres.

If one metre equals 1,000 millimetres, two metres equals 2,000 millimetres.

If one metre equals 1,000 millimetres, three metres equals 3,000 millimetres, et cetera, et cetera.

So you might want to practise the rest of those.

Time for a check.

Fill in the gaps in the stem sentence.

Pause the video.

The answer is if one litre equals 1,000 millilitres, that's our key fact, eight litres equals 8,000 millilitres.

Well done if you got that.

You are definitely on track.

And it's time for some final practise.

So number one, convert the litres to millilitres.

Again, it's a bit jumbly, doesn't matter.

Count them anyway.

Number two, fill in the gaps on the stem sentence.

So you can see five metres has been given.

Can you fill in the other gaps? Number three, some problems. Izzy's dad is a builder and is measuring the walls of a house.

Wall A is five metres in width and wall B is 4,000 millimetres in width.

Which is wider? Number four, Izzy has three one-liter bottles of fizzy drink and Lucas has three two-liter bottles of fizzy drink.

How much fizzy drink do they have in total, in millilitres? Number five, Izzy is trying to stay healthy by drinking a litre of water per day.

Good for you, Izzy.

That's great.

She says, I need to drink 8,000 millilitres of water each week.

Is she correct? Explain.

Pause the video and give those a go.

Welcome back.

How did you get on with that? Let's have a look.

So number one, convert those litres to millilitres.

Well, let's see.

Let's have a count.

I can see 1, 2, 3, 4, 5, 6, 7.

That's seven litres.

And that's 7,000 millilitres.

And the gaps in the stem sentence.

If one metre equals 1,000 millimetres, five metres equals 5,000 millimetres.

Number three, Izzy's dad's a builder.

He's measuring the walls of a house.

Wall A is five metres in width and wall B is 4,000 millimetres.

So different units, but we can convert.

Which is wider? Wall A is wider because five metres equals 5,000 millimetres.

So you can see that's 1,000 millimetres wider, or one metre wider.

You might have written that in your explanation.

And Izzy's got three one-liter bottles of fizzy drink.

Lucas has got three two-liter bottles.

How much do they have in total, in millilitres? Well, three two-liter bottles equals 6,000 millilitres, and three one-liter bottles equals 3,000 millilitres.

And if you add those together, you've got 9,000 millilitres.

And Izzy is trying to stay healthy by drinking a litre of water per day.

Very good, by the way.

Hope you do something similar.

I do.

She says, I need to drink 8,000 millilitres of water each week.

Is she correct? Explain.

Hmm, how many days in a week? Seven.

Seven days in one week, which would be seven litres or 7,000 millilitres.

So she's incorrect.

That's a bit too much.

Maybe she could still drink 8,000 millilitres, but she needs to drink 7,000 millilitres to be on target.

We're coming to the end of the lesson.

It's been a fun lesson.

I hope you've enjoyed it.

I certainly have.

Today's lesson has been about converting from larger to smaller units of measure.

Kilogrammes, kilometres, litres and metres have something in common.

They are each equal to 1,000 of a smaller standard unit of measure.

So let's have a look at that.

So one kilogramme, that's a larger unit, equals 1,000 grammes.

That's a smaller unit.

One kilometre, that's a larger unit, equals 1,000 metres.

That's a smaller unit.

One litre, that's a larger unit, equals 1,000 millilitres.

That's a smaller unit.

And then one metre, that's a larger unit, equals 1,000 millimetres.

That's a smaller unit.

This can be used as a starting point for various conversions as shown by the conversion line.

So when you know those key facts, if you've got those memorised and locked and loaded and ready to go, you can build on that with other ones.

So if you look at this unit conversion line, that could be used with any of those, that could be a kilogramme line, a kilometre line, a litre line, or a metre line.

And you can turn those larger units into smaller units.

Well done on today's achievements and accomplishments.

Why don't you give yourself a little pat on the back? You've done brilliantly.

I hope I get the chance to spend another maths lesson with you in the near future.

But until then, take care! Enjoy the rest of your day and bye-bye.