Lesson video

Hello, how are you today? My name is Dr.

Shorrock and I'm really looking forward to learning with you today.

We are going to have great fun as we deepen our understanding of this topic.

Welcome to today's lesson.

This lesson is from our unit "Measures: Mass, and Capacity." The lesson is called, "Measuring the Volume of Liquids using Millilitres." We are going to deepen our understanding of this concept of volume, and we are going to look at how we can use measuring jugs to measure the volume of liquids and the fact that we measure the volume of liquids in a unit called millilitres.

Sometimes new learning can be a little bit challenging, but I know if we work really hard together, then we can be successful.

And I am here to guide and help you with any tricky parts.

So, shall we find out how we measure the volume of liquids in millilitres? Our key words today are volume and millilitre.

You may have heard those words before, but let's practise them together.

My turn.

Volume.

Your turn.

Lovely.

My turn.

Millilitre.

Your turn.

Brilliant.

Well done.

So when we talk about volume throughout the course of this lesson, we are talking about the amount of space that an object takes up.

But in this case, we are looking at liquids and volume can be measured in the units millilitres.

And you can see a representation there of a jug containing some orange juice.

The volume of liquid in that jug is 100 millilitres.

Now millilitres are measures of capacity or volume and it's a very small amount of liquid.

You could put one drop of water in the palm of your hand and that would be about one millilitre.

And the picture of this teaspoon here, teaspoons if you've got one hand or can go and find one, teaspoons can hold five millilitres of water.

We abbreviate millilitres to a lowercase ml, ml.

So if you see ml written throughout the course of this lesson, you know we are referring to millilitres.

So today we're going to deepen our understanding of measuring the volume of liquids using millilitres, and that's where we will start the learning.

We will then have a look at comparing volumes.

These are the characters who will help us in our learning journey today.

We have Aisha, Sophia, and Andeep.

So who sometimes we need to know the actual volume of a liquid.

So if you need to make a milkshake, you might be asked to use a certain amount of milk, and Sophia wants to make a milkshake for her friends.

Sophia will need to know the volume of milk to use so that she makes it so that it's tasty and she can use measuring jugs to help her.

Should we see how she does it? So Sophia has managed to find some jugs and they all have different capacity and that means they can all hold a different volume of liquid.

What else do you notice about them? Hmm? Are they the same or are they different? And what is different about them? That's right.

Each of the jugs has a different scale on the side.

And maybe you can find a measuring jug where you are now and have a look at it.

I wonder what the scale on your measuring jug is.

And we need to use that scale when we measure the volume of liquid in a container.

It helps us.

So Sophia is choosing to use this jug, a jug with a capacity of 400 millilitres and she needs to measure 250 millilitres of milk.

What do you notice about the scale? Hmm? Is there something that might help us? That's right.

The scale does not show 250 millilitres does it? Hmm.

What are we going to do? We need to accurately measure the volume of a liquid.

We need to determine the value of those unmarked intervals.

You can see we've got some numbers on our scale, but actually if we knew the value of all of those marks, it would be really helpful.

And that scale on the side of the jug is a vertical number line.

And I can lay it down like this, like a horizontal number line, like we are used to seeing, and that can help us.

We can see that the marked intervals increase by 100 each time and we can see that there are two equal parts in between those marks intervals.

And what is it that we know about the composition of a hundred? 100 is composed of two equal parts of, hmm.

Can you remember? Well we know 100 is composed of two equal parts of 50.

So 100 millilitres must be composed of two equal parts of 50 millilitres.

And we can use that fact to help us.

We can count on in fifties to work out the volume.

We need to pour milk until it reaches the end of the first part in between 200 and 300 millilitres because we need 250 millilitres.

And we can see we've got the 200 millilitres.

We can count 250 millilitres because we know each part is worth 50 millilitres.

And so that's where we would pour the milk to.

This would measure 250 millilitres.

And then Sophia has got the correct amount of milk for her milkshake, hasn't she? Let's check your understanding of this concept so far.

What is the volume of liquid in the jug? I wonder if you might be able to find someone and say the sentence to them filling in the blank.

The volume of liquid in the jug is, mm, millilitres.

So remember what we've just learned about the composition of 100.

Pause the video.

When you've had chance to say the sentence to somebody, press play.

How did you get on? Did you say that the volume of liquid in the jug is 50 millilitres? And we can see that because the volume of liquid in the jug reaches the end of that first part and we know the part is worth 50.

Let's look at another example.

What do you notice here about this jug? Yes, the capacity of the jug is 400 millilitres.

But what is the volume of liquid in the jug? Hmm.

We can see it's more than 100 millilitres, but it's not quite 200 millilitres.

And remember the numbers on the side of that jug is just a number line and we can use that to help us.

We know 100 millilitres is composed of two equal parts of 50 millilitres.

The liquid reaches the end of the part in between 100 and 200.

So what volume of liquid must that be then? So we can help ourselves by starting our count at 100 and counting on in 50.

So 100, 150.

The volume of liquid in the jug is 150 millilitres and we could represent that in an equation.

100 millilitres and we're adding on that extra part, that extra 50 millilitres.

So we've got 150 millilitres.

Let's check your understanding.

Could you tell me what the volume of orange juice in this jug is? Is it 310 millilitres? 350 millilitre? Or, the top of the liquid does not reach a marks interval, so we can't tell.

Pause the video.

When you think you know press play.

How did you get on? Did you say, "Well, it must be 350 millilitres"? It can't be 310 millilitres, although I could see why we might say that because it's just one part more than 300.

But there are two parts between each interval and each part is worth 50 millilitres because 100 is composed of two equal parts of 50.

We can count on from 300.

300, 350, 400.

But we need to stop at 350 there, don't we? The volume of orange juice is 350 millilitres.

Well done if you've got that.

Let's look at another example.

What do you notice about this jug? That's right.

The capacity of the jug is 200 millilitres.

But what is the volume of liquid in the jug? Well we can see that it is less than 200 millilitres, can't we? 'cause it's not reached the capacity of the jug.

And Aisha is reminding us, "Remember we can use the scale as a number line to help us." And we can see each marked interval of 100 is composed of 10 equal parts.

And what do we know about 100 and being composed of 10 equal parts.

10 equal parts of what? That's right.

100 is composed of 10 equal parts of 10.

So that means 100 millilitres is composed of 10 equal parts of 10 millilitres.

We can see the liquid reaches the end of the seventh part in between 100 and 200.

And we can count on in 10s from 100.

So shall we do that together? We're going to start at 100.

110, 120, 130, 140, 150, 160, and 170.

We can represent this as an expression.

I've got 100 millilitres, which is where we started counting from.

And then my seven 10 millilitre parts, 100 millilitres, add 70 millilitres, is equal to 170 millilitres.

So the volume of liquid in the jug is 170 millilitres.

Let's look at a different example and work out the volume of liquid in this jug.

Ooh.

Andeep thinks it's 120 mls.

Aisha is disagreeing.

She thinks the volume of the liquid is 140 millilitres.

Hmm.

Who do you think is correct? I can see why both of them might think they are correct.

Can you? So first we always need to work out how many equal parts there are between those marked intervals on that vertical number line.

How many parts are there? Can you see? That's right, there are five equal parts in between the 100 intervals.

And what do we know about the composition of 100 and if it has five equal parts? That's right, 100 is composed of five equal parts of 20.

So 100 millilitres is composed of five equal parts of 20 millilitres.

And the liquid, which is the end of that second part after 100.

So we can count on from 100 in twenties to work out the volume.

Shall we have a go? 100, 120, 140.

So we can represent that in an expression.

I've got my 100, which is where we started counting from, plus 20 plus 20.

100 plus 40 millilitres is 140 millilitres.

So the volume of liquid in this jug is 140 millilitres.

Aisha was correct.

Well done Aisha.

Let's check your understanding.

Is this true or false? The volume of orange juice in the jug is 110 millilitres.

Decide if it's true or false and then think why.

Is it because the orange juice reaches the end of the first part and the parts are worth 10 millilitres? Or there are five parts between the marked intervals of 100 and each part is worth 20 millilitres and the volume is 120 millilitres? What do you think? Pause the video.

And when you are ready, press play.

How did you get on? Did you say that it's false.

It's not 110 millilitres.

It is in fact 120 millilitres.

There are five equal parts in between those marked intervals.

So each part is worth 20.

Let's look at another jug.

What volume of liquid is in this jug? What do you notice? That's right.

Aisha can see that the top of the liquid reaches that 100 millilitre mark, so the volume of liquid in the jug is 100 millilitres.

We say that the jug is at full capacity.

We can't get any more in that without it spilling over though.

Aisha pours some liquid out of the jug.

What volume of liquid is left? What can you tell? That's right, Aisha's reminding us we need to use the scale to help us.

And we know that 100 is composed of four equal parts of 25.

Can you see those equal parts? So 100 mil must be composed of four equal parts of 25 millilitres.

So each part on that scale is worth 25 millilitres.

And where is that orange juice reaching? That's right, the liquid reaches the end of the second part.

So the volume of liquid in the jug must be 25 millilitres for the first part and another 25 millilitres.

So that's 50 millilitres.

What else do we notice? That's right, the liquid is filling half of the capacity of the container.

Half of 100 millilitres is 50 millilitres.

Well done, if you spotted that.

Let's check your understanding.

What is the volume of liquid in the jug? Maybe you could find someone and say this sentence to them.

The volume of liquid in the jug is, mm, millilitres.

I'm filling in the blank.

Pause the video.

And when you've had chance to say the sentence, press play.

How did you get on? Did you work out that the volume of liquid in the jug is 25 millilitres? Why is it 25 millilitres? That's right, because the liquid is only reaching the end of that first part and we know each part is worth 25 millilitres because there are four equal parts and 100 is composed of four equal parts of 25.

Well done.

Your turn to practise now.

For question one, I would like to look at these three jugs and can you tell me the volume of orange juice in each jug? And then could you tell me what the difference is between the greatest volume and the smallest volume of orange juice? For question two, could you colour these jugs to show that they each contain a volume of 150 millilitres water? But take care.

What do you notice about each of the jugs? Are they the same? Are they different? And then in particular, what do you notice about the third jug? And then question three, a problem for you.

Andeep has a can that contains 500 millilitres of lemonade.

He pours out 150 millilitres for Sophia and then drinks 200 millilitres.

What volume of lemonade is left in the can? Could you represent that in a bar model because it will help you to understand the structure of this question.

And then could you write down the equation and solve it? So there are three questions for you to have a go at.

If you pause the video and when you have finished, press play.

How did you get on? Shall we have a look? For question one, you are asked to identify the volume of orange juice in each jug.

For 170 millilitres, 150 millilitres, and 120 millilitres.

And the difference between the greatest volume and smallest volume of orange juice.

Well the greatest is that first jug, 170 millilitres.

And we're going to subtract the smallest volume, which was 120 millilitres.

So that is 50 millilitres.

For question two, you were asked to colour the jugs to show that each contained a volume of 150 mls of water.

In the first jug, there were 10 equal parts, so you had to colour up to the 100 and then five more parts.

For the second jug you had to colour up to the 100 and then one more part because there were only two equal parts.

Ah, the third jug was a bit trickier, wasn't it? Because the parts were worth 20.

So you had to colour up to 100 millilitres, then 20, then 20.

And then you couldn't do another 20, so you had to do halfway in between.

Well done if you spotted that.

That third jug was increasing in twenties and 150 millilitres was in between.

And for question three, you had a problem to solve and you were asked to represent it in a bar model and you could see the whole amount must be the volume of lemonade in that can.

That is the whole amount of liquid.

And then a 150 millilitres was a part that he gave Sophia and 200 millilitres was the part he drank himself.

So then you were asked to write down the equation and solve it.

So first we find the sum of the known parts.

So 150 millilitres and 200 millilitres is 350 millilitres.

And then we subtract that from the whole.

500 subtract 350 is 150 millilitres.

So the volume of lemonade left in the can is 150 millilitres.

How did you get on with all those? Brilliant.

Well done.

I am really impressed at how you have deepened your understanding and your ability to measure the volume of liquids using millilitres.

Let's move on now and look at how we can compare volumes that are measured in millilitres.

Sometimes we need to compare the volume of liquids.

Andeep is thirsty and he would like the drink with the greatest volume of liquid.

That would help quenches his thirst, wouldn't it? I wonder which glass holds the greatest volume? What do you think? Is it the glass with the green drink? Or the pink drink? Shall we find out? So if the containers are different shapes and sizes, it's not always possible to tell which contains the greatest volume just by looking.

What are we going to do then? Well, yes, let's pour them into a measuring jug and that will tell us the volume of liquid in each glass.

So Andeep starts by pouring the liquid from this glass into the jug.

What do you notice? That's right.

Andeep is saying we need to use the scale to help work out the volume of liquid.

We can see there are five equal parts between those marked intervals of 100.

And what do we know? That's right.

We know that 100 is composed of five equal parts of 20.

So each part here is worth 20 millilitres.

The liquid reaches the end of the fourth part.

We count up in twenties from that 100.

So 100, 120, 140, 160, 180 millilitres.

And let's do that for the second glass.

Andeep pours that liquid into the jug.

The scale is the same, it's the same jug.

So each part is still worth 20 millilitres.

And this time the liquid reaches the end of the third part, so we can count up again in twenties from 100.

120, 140, 160 millilitres.

So now that the liquids have been poured into jugs, that are the same shape and capacity, it is easier to see which has the greatest volume.

We can just look at them by eye, can't we? Because they are in the same jug and we can see the pink liquid reaches higher up the container.

So, Andeep was really thirsty, remember.

Which drink should he choose to quench his thirst? That's right.

180 millilitres is greater than 160 millilitres so he should choose that drink that was the pink container, the pink drink.

Its volume is greater.

Let's check your understanding.

Can you have a look at these two jugs? Which jug contains the greatest volume of liquid? Just stop and see first, what you notice about each of the jugs.

And then, tell me which jug contains the greatest volume of liquid.

Pause the video.

And when you have done that press play.

How did you get on? Did you see that the jugs are the same? So when the jugs are the same, we can just look at that level of liquid and we can see the level of liquid in jug A is higher than that in jug B.

Jug A contains 160 millilitres of liquid.

Jug B 120 millilitres of liquid.

So this confirms our thoughts that jug A contains the greatest volume of liquid.

160 millilitres is greater than 120 millilitres.

So let's compare the volume of liquid in these cups.

This time Andeep and Sophia use different jugs.

Here are the jugs.

What do you notice about them? How are we going to find out which cup contained the greatest volume of liquid when the jugs are different? So we cannot just look at the level of the liquid.

We are going to have to use the scales.

If we use the scales, we can determine the volume of liquid in each jug.

Then we can compare the volume of those liquids.

We can see in the first jug, the volume is 180 millilitres.

There are 10 equal parts in between the marked intervals of 100 and the liquid reaches the end of the eighth part, 180 millilitres.

In the second jug, there are two equal parts in between the marked intervals of 100.

So each part must be worth 50 millilitres.

So the volume of liquid in that jug is 150 millilitres.

We can then compare the volumes.

180 millilitres is greater than 150 millilitres.

So the volume of liquid in the first cup was the greatest.

180 millilitres is greater than 150 millilitres.

And it was tricky.

We couldn't have told that just by looking at the containers.

We had to use measuring jugs.

But then because we used different measuring jugs, we had to actually work out the volume using the scale.

Let's check your understanding.

Can you tell me which jug contains the greatest volume of orange juice? Jug A or jug B? Take care to notice what is the same and different about the jugs.

And take care to have a think about the value of those unmarked intervals.

Pause the video and when you are ready for the answers, press play.

How did you get on? Did you work out that jug B contains the greatest volume of orange juice? Jug A had 150 millilitres, jug B 160 millilitres, and 150 millilitres is less than 160 millilitres.

Well done if you've got that correct.

Your turn to practise now.

For question one, I would like you to go and find three containers, the type of capacity of no more than 1000 millilitres.

Could you put some water in each? Doesn't matter how much.

Part A can you predict which of your containers then has the smallest volume and which has the largest volume of water? For Part B, can you use a measuring jug and determine the volume of water in each container? And then part C, starting with the smallest volume, can you put your containers in order of the volume of water that they contain? And then for Part D, revisit your predictions.

Were you correct? For question two, can you look at these jugs? Can you tell me the volume of liquid in each jug? Take care to notice that scale and work out the value of the unmarked intervals.

For Part B, can you start with the jug containing the smallest volume of water and put the jugs in order of the volume of water that they contain.

And for your third question, can you look at the kettle and the teacup? The jugs next to them show the volume of water that they were holding.

Can you tell me how much more liquid was the kettle holding than the teacup? So you have three questions to have a go at.

Pause the video, and when you have finished them, press play.

Shall we see how you got on? For the first question, you were asked to find three containers and put a little bit of water in each, and then predict which container had the smallest and greatest volume of water.

Yours might have looked something like this.

So I had a smallest volume.

I had a yellow water bottle, which I thought was in the middle, and then my one with the what I thought was the greatest volume.

You were then asked, actually determine the volume of water in your containers.

I had a container with 200 millilitres, 100 millilitres, and 250 millilitres.

And then you were asked to start with the smallest volume and put your containers in order.

And I noticed I had to rearrange mine because my yellow water bottle had the smallest volume of water in.

So yours might look something like that.

Then I noted that my predictions were inaccurate.

You might have thought yours were accurate.

Well done.

For question two, you were asked to tell me the volume of liquid in each jug.

A was 175 mls, B 180 mls, and C 150 mls.

How did you get on? For part B, you were asked to put some jugs in order, starting with the smallest volume of water.

Jug C only had 150 millilitres, jug A 175 millilitres, and jug B 180 millilitres.

And I can write this as an inequality, and I can see 150 millilitres is less than 175 millilitres, which is less than 180 millilitres.

So the smallest volume was jug C.

The greatest volume was jug B.

For question three, you were asked to look at a kettle and a teacup and find out how much more liquid was the kettle holding than the teacup.

The teacup was holding 120 millilitres and the kettle 190 millilitres.

So then I had to work out that difference.

I represented this as a bar model.

I can see the whole amount is 190 millilitres and the teacup part was 120 millilitres.

If I subtracted the 120 from the 190, I got 70 millilitres.

So the cattle held 70 millilitres more than the teacup.

How did you get on with those questions? Brilliant.

I can see how much progress you have made with your ability to measure the volume of liquids using millilitres today.

Well done.

We have learned that the volume of a liquid in a container can be measured in millilitres, and we've learned that when we're measuring the volume in millilitres, if the containers are the same, we can just look at the level of liquid in the container.

But if the containers are different, we need to take into account the scale on the measuring container and work out the value of those parts, those unmarked intervals.

It's been really good fun learning with you today.

I look forward to learning with you again another day.