Lesson video

Okay, welcome to our six lesson with estimating capacity.

We are going to be using all our prior knowledge in order for us to make great estimates and then finding out the differences, when we find out the actual capacities.

We're going to start off with the lesson agenda.

First, we're going to start off with estimating the capacity, then we're going to go onto using prior knowledge for estimating, then we're going to be finding out the actual sizes of the capacity, and then we're going to be finding a difference, which you then get you ready for your independent task, and then we'll go through the answers.

So you will need a pencil, a rubber and an exercise book ready for this lesson.

So before we start, would it be better to use millilitres or litres to measure the capacity of these containers? So we have a fish tank, we have an egg cup, one is empty obviously, a soup bowl and a wheely bin.

So what do you think? Have a moment to have a think about that and why? Okay so when we're estimating capacity, the larger the container, the more practically is to measure the capacity in litres, both units millilitres and litres will give you a correct measurement, but because in litres, 1000 millilitres, writing the capacity of large containers using millilitres will be messy and time consuming while using litres is more efficient.

Okay, what we're going to be doing now is we're going to be comparing different capacities.

And I'm going to be asking questions based on that.

So I'm going to be comparing a 100 millilitre bottle to this can of pop compared to this 500 millilitre bottle, compared to this litre bottle right here.

Do you think the cola can, is larger or smaller than the 100 millilitre bottle? Do you think the cola can is larger or smaller than the litre carton? Do you think the cola can, is larger or smaller than the 500 millilitre bottle? How much? Can you use this to estimate the capacity of the can? So let's find out the capacity of the can of pop.

I've got a measuring jug here.

That's going to help me.

And we shall be pouring it in to find out, let's see our estimations were correct.

So it's more than a 100 millilitres, but less than 500 millilitres.

So let me just go up close, measure all the waters out.

And as you can see, it is about 330 millilitres of liquid in the can.

Okay, so as we know, estimating is a skill that we need to practise, and most of us won't be very good at it, to begin with, but a good estimate at this stage is one that is currently greater or less than 500 millilitres.

And that's what we will be comparing with today.

Okay so now we're going to be using prior knowledge for estimating.

We're still going to be using the 500 million litre bottle as a comparison to help us out.

So whenever you start, you always acknowledge how much we are comparing to, language is important here.

So here we go.

We're comparing to a can of coke.

So as language is important here, and we're going to be comparing the can of the coke.

So I know that the capacity of the water bottle is 500 millilitres.

Always start by acknowledging this.

The can of pop looks about half the size of the water bottle, let's have a look about half the size of the water bottle.

So I estimate that the can has a capacity of 300 millilitres.

So because I thought that it was half the size, I was going to go for an estimate, less than 500 millilitres.

Let's see what Susie says, "I've measured the capacity of the can.

You were right.

It is smaller than the water bottle with a capacity of 330 millilitres." This is in prior knowledge to create good estimates of capacities of bottles.

Therefore, we are going to write that the bottle is greater than the can of coke.

Let's see what happens with the next one.

So let's have a look at this one, I know that the capacity of the water bottle is 500 millilitres, the milk bottle looks a little larger, so I estimate the capacity of the milk bottle is 600 millilitres.

Do you think that this is a little larger? Let's have a look, I've measured the capacity of the milk bottle, you were incorrect as it is only 450 millilitres, which is smaller than the water bottle.

And that's where we have to be careful, as I said the more we practise, the more our estimates can start being a lot more accurate.

Now this isn't necessarily completely wrong.

Susie was about 150 millilitres off, but this is clearly smaller, than the water bottle.

So in that case, we then say that the bottle is greater than the milk bottle.

Okay,so in this case, Susie was wrong.

All right, your turn.

Before we start, I want to show you a little picture of, of what it looks like.

Okay, good.

Now you're going to estimate the capacity of the mug.

So what I'm looking for is if the bottle is less than, the bottle is more than, or the bottle is equal capacity to the mug.

Pause the video and answer it for me please.

Okay, let's find out if we are correct by watching the video.

Okay so I'm going to measure this according to this bottle, we've estimated, and we're now going to check what it is.

Now just feel is easier and safer.

I'm going to be using this 500 millilitre container, which is the same as this.

I'm going to place down there and I'm going to put the water from the mug into it, here we go.

And as you can see, it is about 300 and well, let's have a look.

If we have one, two intervals in between 300 and 400, that means that in the middle it will be 350 and it's just underneath.

So I'd say it's about 340 millilitres.

Good, so in that case, you know that the answer is, the bottle is greater than the mug.

Well done guys.

So now we're going to be finding a difference from the estimate and the actual capacity.

So let's go back to the can of coke.

We know that the can of coke our estimate was 300 millilitres.

And then when we actually measured it, it was actually 330 millilitres.

So then we need to go back as we did before with maths to work out the difference, and we're going to use this lovely bar model right here where the greater quantity will represent the big bar model, the first one, and the smaller quantity represents the smaller value.

So in this case it would be 330 millilitres is a great quantity, and 300 millilitres is a smaller quantity.

And what calculation do we get from that? It will be 330 millilitres take away 300 millilitres, which is equal to 30 millilitres, therefore all different series 30 millilitres.

Now I need your help, let's go to the next one, going back to the milk bottle.

we estimated that it would be 600 millilitres we thought, but it wasn't the greatest one because actually smaller than the bottle.

And it ended up being 450 millilitres.

So what is the difference? So the greater quantity, the greater quantity is always the actual capacity, right? No.

Remember that it's a common misconception.

The greater quantity could be either the estimate or the actual capacity.

And in this case, it is estimate, which is 600 millilitres, which means our actual capacity is 450 millilitres.

What do I do now? I need to work out the calculation.

And what is that? Perfect, 600 millilitres take away 450 millilitres.

And when we work that out, the answer should be 150 millilitres.

Well done guys.

Now it's time to do it by yourself.

Here's an estimate of 480 millilitres and actual capacity of 514 millilitres.

I would like you to pause the video and work out the difference, off you go.

Okay, the answer should be, are you ready? 34 millilitres.

Okay so let's find out how we got there, So our greater value was 514 and our smaller value was 480, which gave us this calculation above 514 take away 480, which gave us 34 millilitres.

Well done guys.

Are we ready for independent task? I can't to show you what it is.

Here we go.

Right guys it's time for you to help me with an independent task.

Now you may want to do this at home, but make sure that you are asking a parent and you're doing this with a parent because safety first, because we're dealing with a big volume of water.

You need to make sure that you have a clean, safe area.

And like I said, you're working with a parent.

If not, just watch the video and you can estimate along with me, right here we go, let's start, so we're going to be using four containers that we will be estimating the capacity of, the first container is this old pickle jar 'cause Mr. Nieto loves this pickles.

The second one is a cereal bowl, the third one is this old dessert container , that I found.

And the final one is our small little frying pan.

It's a small one.

Now we are going to be comparing the capacity with our 500 millilitre bottle of water that you have at home.

Now, just for the purposes of the video, I'm going to be using this container, which is exactly 500 millilitres as well.

So when I pour in to the water, then I'll be able to compare it this way as well.

Here we go, let's begin, so the first thing you're going to do is, is you're going to look at each container and I'd like you to estimate what you think the capacity is compared to the 500 millilitre bottle of water.

So here's the first one.

Okay, here's the second one.

And I'll just tilt a little bit, just so you can see, here's the third one.

And here's the last one? What do you think your estimate is? You're going to go to the white sheet first, and you're going to write in your estimates in your book.

Do that now for me please, and then come back.

So we're going to start with the jar of pickles, comparing it to the 500 millilitre bottle.

We're going to pour it into this measuring cylinder and find out whether our estimate was accurate enough, just being really careful, make sure you using an adult to help you if you're doing this at home.

And as you can see, the capacity is 840 millilitres.

Right on to the cereal bowl compared to the 500 millilitre bottle, carefully pouring it in, as you can see I have something underneath to prevent it spilling a little bit falls off, a little bit of water on the side, but let me just have a look.

And it is about 400 millilitres of water.

Now let's move on to the dessert parts compared to the 500 millilitre bottle.

Okay nice and carefully pour into your measuring jug.

And let's have a look at what our capacity is, 125 millilitres, Well done guys, on to the frying pan, the tricky one of the four, for sure.

I put something underneath and I'm nervously putting the water into the measuring cylinder.

Now some water did make it out of the measuring cylinder, but it's fine.

Only a little bit and pouring in safely and carefully.

Let's have a look, and as you can see on the tray on underneath, there was some spillage, which I will take into account.

So therefore the capacity is 890 millilitres.

So almost one litre.

Now that you've seen the video, I would like you to pause go to the worksheet and fill out your estimates and your actual capacities, and then meet me back here.

Great, so we've worked our estimates and we've also got our actual capacities.

What's really interesting here is we might have different estimates, the idea is that you want to have them quite close to the actual capacity.

Again, this will get better over time, Okay practise makes permanent, and that's what matters here.

Now what I'd like you to do is, is we're going to pause the video again, and you're going to use these values, my values, okay, of the estimate natural capacity to work out the differences for each one, okay.

And then we'll come back to here and we're going to go work out for the answers.

So let's start, our greater quantity is 840 millilitres, Great, therefore our smaller quantity is 780, our calculation is 840 takeaway 780 millilitres, therefore our difference is 60 millilitres.

Well done guys.

Make sure that you've checked that calculation correctly, if it doesn't look like mine, fix it now.

Let's go to the next one.

Alright the cereal bowl also greater quantity is 440 millilitres, our smaller quantity is 400 millilitres.

what calculation do we get, we have 440 millilitres take away 400 millilitres, which gives us the answer of 40 millilitres.

Well done guys, if it doesn't look like mine, fix it now, please.

Let's go into the next one.

So let's go with the desert port, now our estimate was a 100 millilitres, our actual capacity was 125, the greater quantity there is 125 millilitres, the smaller quantity is a 100 millilitres.

We need to work out the calculation, which is 125 take away a 100.

Therefore our difference is 25 millilitres.

Well done guys, If it doesn't look like mine, fix it now please.

Onto the final one, our small frying pan.

Now we estimated it was going to be 800 millilitres, the actual capacity was 890, therefore a greater quantity here is 890 millilitres.

Therefore our smaller quantity was 800 millilitres.

We need to write out the calculation with our bar model 890 millilitres take away 800 millilitres, which gives us 90 millilitres.

Great work guys, it's been amazing working with you today.

I can't wait to see your incredible work and make sure that if you don't understand certain parts, go back to the video and see if you can go through it again.

Well done guys, good work today.