Lesson video

Hello, and welcome to our next lesson of Weighing and Comparing Masses in Mixed Units.

Now, by the end of this lesson, we're going to be able to compare different masses in different units and be able to make good estimates to see which one's heavier or which one's lighter than each other.

Let's start.

So we're going to go over what we're doing today.

First, we're going to do kilogrammes and grammes.

Then we're going to be rehearsing the language of mixed units for mass.

There will be weighing and comparing with mixed units, which will then get you guys ready for your independent task.

And then we can go over the answers.

So let's get started.

So first, you're going to need a pencil, a rubber, and an exercise book.

So length or mass? What could we measure with these pieces of equipment? Name items that you would use each piece of equipment to measure.

So have a look at them all there, we've got 1, 2, 3, 4, 5, just tell me how do you know what they're used for and what units will you use? So we have a tape measure.

We might use that to measure the length of a book, a small item.

We have some weighing scales here, and some of them are used for small items. So I'd say this one could be used in the market to measure all the apples that you buy.

This one could be used when you're making a cake at home with mom or dad.

And this maybe is for higher, heavier items, that you will maybe use for if you're going to get a big bunch of potatoes maybe.

And we have a measuring tape, which is normally used by tailors when they're trying to measure the size of your leg or your arms. And the type of units we'll be using normally for length, we go with centimetres or metres and for weight, as you know from our previous lesson, we will be working with grammes and kilogrammes.

So kilogrammes and grammes.

I'm going to show you a quick video, how we can use a weighing scale to prove that one kilogramme is equal to 1,000 grammes.

So let's watch.

So these are the weights that we're going to be using, and this is our scale.

So we have one kg, 500, 200, 105 kg.

And for it to be balanced, the line has to be right there in the middle.

So let's start with one kilogramme.

We're going to put it on one side.

And as you can see, it goes downwards.

When it's lower, that means it's heavier than the other side.

Lower means heavier.

500 grammes.

Now, I'm going to use two, 500 grammes to make sure that that equals to one kilogramme.

Let's prove it.

Here comes a second one and it should be equal and balanced.

That means that one kilogramme is equal to two, 500 grammes.

Okay, good.

Would be mathematicians, we're proving things.

Let's move on to 200 grammes.

I know I need 200 grammes, 400 grammes, 600 grammes, 800 grammes, 1,000 grammes, which is equal to one kilogramme.

So let's try it out.

We're going to prove it, here we go.

There's 200, there is 400, 600, 800 and 1,000 grammes.

And this should balance out, we've proved it.

It's equal to one kilogramme.

So now that I've proved to you guys, as mathematicians, we need to make sure that we can prove things are correct.

We are now going to do this question.

We have kilogrammes to grammes.

So in that case, four kilogrammes is equal to 400 grammes, 4,000 grammes, 400 kilogrammes or 4,000 kilogrammes? You can pause and try and work it out in your books.

So the answer was, drum roll.

4,000 grammes, absolutely, because we know that one kilogramme is equal to 1,000 grammes, then 4,000 kilogrammes is equal to 4,000 grammes.

Well done guys.

And we proved that before, didn't we? So we know that that is accurate.

So now we're going to really get into our language and how we use it to explain mixed units in maths.

So here we have an example and the first weighing scales here, we can see that there is two kilogrammes, which means that each one of these ones are equal to one kilogramme.

So therefore, we have two kilogrammes here and we have three kilogrammes here and these are the parcels that we are trying to measure.

Now, the little green ones are all equal to 100 grammes too.

So just bear that in mind.

So let's start with the rehearsing.

So this is the language I would like you to use.

The mass of this parcel is greater than two kilogrammes.

And less than three kilogrammes.

I know this, because the parcel is lower on the balance, as you can see here, lower on the balance than two kilogrammes, but higher on the balance than three kilogrammes.

We're going to have Susie helping us out.

This is one kilogramme, two kilogrammes, 100 grammes and 200 grammes.

The balance is about level when there is two kilogrammes and 200 grammes in the other bucket.

So this parcel weighs about two kilogrammes and 200 grammes.

And that is the language we're going to be using.

Let's try the next one.

Let's have a look then.

We have these weighing scales on either side, we're going to use this to help us with this vocabulary.

So the mass of this parcel is greater than, that's right, four kilogrammes.

And it's less than, like that, five kilogrammes.

I know this, because the parcel is now, have a look, is it lower or higher? It is lower on the balance than the four kilogrammes, but it is higher or lower on the balance compared to the five kilogrammes? It is higher on the balance than five kilogrammes.

Good, really good guys.

It's really important that we use this language higher or lower.

Then we're going to move on to this one.

Let's have a look.

So that is 1, 2, 3, 4 kilogrammes, and 100, 200, 300, 400, 400 grammes.

The balance is about level when there is, what do we say all together? Four kilogrammes or 400 grammes in the other bucket.

So this parcel weighs about four kilogrammes and 400 grammes, really working at the vocabulary.

Have a moment to read through it one more time before we go into your task.

Right, now it's your turn.

So have a look at these images, what is the mass of the parcel? I would like you to pause the video and work it out for me now.

Now remember, use that vocabulary higher, lower.

Off you go.

Let's see how we got on.

So what is the mass of the parcel? Let's have a look.

We have right here.

Well, I know that it is.

Is it higher or lower compared to the three kilogrammes? It is lower, therefore it is heavier than three kilogrammes.

Okay, good.

I know that because the parcel is higher, then that means that it is lighter than the four kilogrammes.

So we know it's in between three kilogrammes and four kilogrammes.

So let's find out, let's see, look at the next package to help us.

Let's have a look.

It is one kilogramme, two kilogrammes, three kilogrammes.

And let's count the 100 grammes, 100, 200, 300, 400, 500, 600 grammes.

Because it is level, we can say that the parcel is three kilogrammes.

Which one is it going to be? And 600, ah, you're right, grammes.

So let's see if we are correct.

Well done, three kilogrammes and 600 grammes.

Fantastic work guys, well done.

So now we're going to be weighing and comparing with mixed units.

So we're going to to be using what we learned before.

So remember our five steps.

So the first one is what is the scale? Well, in this case, we are actually going to be using mixed units.

So it's going to be grammes and kilogrammes.

What two intervals is it in between? Well, when we look at our indicator, we know that it's in between one kilogramme and two kilogrammes.

And what are the value of the intervals? Now, we have to go back to what we were thinking.

So let's have a look at one kilogramme to two kilogrammes.

That means the total in between these two is one kilogramme.

So that means we need to think, let's count the intervals.

Are you ready? 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

So 10 intervals that make one kilogramme, 10 intervals that make 1,000 grammes.

I think I'm going to use my 10 times tables.

I'm going to go 10, 20, 30, 40, 50, 60, 70, 80, 90, 100.

Well, if I went and did that with 100 and we can go 100, 200, 300, 400, 500, 600, 700, 800, 900, 1,000.

There it is.

That means that each interval is equal to 100 grammes.

Now, in that case, I am looking for this indicator there.

So I know that I'm going to go from one kilogramme, I'm going to count up 100 grammes, 200 grammes, 300 grammes.

So now I'm going to put them together as a mixed unit.

So altogether, this kitten right here weighs one kilogramme and 300 grammes.

Remember it's about, this is an estimate.

Are we ready for the next one? Here we go.

First step, what is the scale? In this case, we going to be using grammes and kilogrammes.

Well done.

What two intervals is in between? Well, let's have a look at our scale.

We have one kilogramme and two kilogrammes.

Well done guys.

What are the values of the intervals? Ah, this is very similar to the last weighing scale, but let me just double-check.

Let's have a look.

In between, and we have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

We know that there are 10 intervals in 1,000 grammes, which is equal to one kilogramme.

Therefore, each interval is going to equal 100 grammes.

Now, this time we need to count up to our interval.

So is one kilogramme and let's count up, are we ready? 100, 200, 300, 400, 500, 600, 700, 800, 900.

Okay, there we go.

Our final measurement is going to be one kilogramme and 900 grammes.

Well done guys that was really good work from you.

Are we ready? It's time for you guys to do this independently.

Here we go.

What is the mass of this kitten? Now it's a completely different kitten guys.

So it's not the same one as before.

We can tell by the measurements on our scale.

So pause the video now and work it out.

Don't forget those five steps.

What is the scale? Where is the indicator in between? What is the value of each interval? Counting up in grammes or kilogrammes, and then your final estimate.

Off you go.

So what is the mass of this kitten? Here we go.

So, first thing, what is the scale? Well, we know that the scale is grammes and kilogrammes.

Excellent.

Well, what is the indicator in between? Well, we can see that it's in between one kilogramme and two kilogrammes, good.

Third step, was what is the value of our intervals? Well, there are 10 intervals in between one kilogramme and two kilogrammes.

So therefore, we know that each interval is equal to 100 grammes.

Good guys, well done.

We now need to count up in grammes or kilogrammes, so let's count.

And it goes 100, 200, 300, 400, 500, 600, 700 grammes.

That means our final mass of this kitten, is one kilogramme and 700 grammes.

It's this one, right? This one? No, be careful.

Watch your units.

It is definitely not.

It's not 700 kilogrammes.

That would be crazy, crazy heavy.

Our kitten has not eaten that much.

This is the value and it is one kilogramme and 700 grammes.

Well done.

If you're still making mistakes, maybe go back to the slides and go through the steps with me again.

It's time for our independent task.

Here we go.

Right guys.

So independent task time.

I am really needing your help.

I need you to find out the mass of our four animals.

They all look pretty similar.

I think they're all related.

What I'd like you to do is use the same techniques for us that we're going to be finding these out in mixed units.

So it will be in kilogrammes and in grammes.

You're now going to pause the video and you're going to go to your worksheets and try them out for me.

And then we're going to come back here for the answers.

Good luck.

Hello everyone.

My name is Ms. Jones and I'm going to be explaining today's answers for you.

So let's look at number 1.

We've got some sort of singing bird on the scales here.

So what is the scale? What are the units of measurement we were using here? Well, we are using grammes and kilogrammes.

Okay, number 2.

What two intervals is it in between? So I'm looking for those milestones.

So if we look either side it's between one kilogramme and two kilogrammes.

So I know my answer is more than one and less than two kilogrammes.

What are the values of the intervals? So in order for me to work that out, the easiest thing for me to do is count them 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Now, I know that one 10th of a kilogramme is equal to 100 grammes.

So my intervals are 100 grammes each.

Now, I need to count up in grammes to work out how many grammes more than one kilogramme I've got here.

100, 200, 300, 400 grammes.

So I know my final amount if I look at the kilogramme and the grammes combined is one kilogramme and 400 grammes.

Moving on to the next one.

So we've got a bouncing little happy tiger there.

What is the scale? So again, we are using grammes and kilogrammes here.

The two intervals in between or either side are four kilogrammes and five kilogrammes.

What are the values of the intervals? Now this scale does look different.

So I'm going to check again 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, again.

So again, it's one 10th of a kilogramme, which is equal to 100 grammes.

I could have looked at the halfway mark perhaps to help me, which would have been halfway 4.

5 kilogrammes, and then worked it out.

But let's count up in grammes.

We've got 100 grammes, 200 grammes.

So I know my final amount is four kilogrammes and 200 grammes.

And the next one.

Again, we've got here, something on the scales, a teddy bear.

What is the scale here? And again, we're working with kilogrammes and grammes.

What are the two intervals? We're between two kilogrammes and three kilogrammes? What is or what are the value of the intervals? 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

So I divide by one kilogramme.

That's here into tenths, which means each interval is 100 grammes.

Let's count up in grammes, 100, 200, 300.

Do I know my final amount here is two kilogrammes and 300 grammes.

And finally, we have a very sad-looking dog here.

What is the scale? We are working in kilogrammes, so my in between will be grammes.

So we've got kilogrammes and grammes.

What two intervals is it's in between? Well, I can see it's in between three kilogrammes and four kilogrammes.

What are the value of the intervals? Now, interestingly, with this one, we could count each interval to work out the value 100 grammes, I think it is again, but what we can also do here is look at the halfway point.

Think about what's halfway between three and four kilogrammes? But we know that each interval would be 100 grammes.

We know that this is 1, 2, 3, 4, 500 grammes, more than three kilogrammes.

Or you could look at that as halfway between three and four kilogrammes.

So we've got three kilogrammes and 500 grammes to finish off there.

I'm now going to pass you back over to your teacher to finish the lesson.

That brings us to the end of today's lesson.

A really big thank you to all the fantastic learning you have done today.

You've been incredible.

I've got two final things I'd like you to know.

First, if you're able to please take a picture of your work and ask your parent or carer to share it with your teacher so they can see the fantastic things you have learned today.

Second, if you'd like, ask your parents or carer to send the picture of your work, to @OakNational on Twitter, so then I can see your lovely work too and it'd be great to see how we're learning together.

That's it for today.

Thank you so much.

Take care and enjoy the rest of your learning for today.

Bye.