Lesson video

Hello, my name is Dr.

Shorrock.

I am so excited to be learning with you today.

You have made a great choice to learn maths with me and I'm here to guide you through the learning.

Today's lesson is from our unit, Measures, Maths and Capacity.

The lesson today is called Become Familiar with Scales with Different Intervals when Measuring in Grammes.

We are going to look at lots of scales and you'll see that they are different, they have different intervals, and we will look at what that means.

Some of this learning may be new today, and that's okay.

I'm here to guide you if it gets tricky.

So how do we use scales that have got different intervals when measuring in grammes? These are the key words that we will be using throughout our lesson today.

We've got mass, gramme, and interval.

Let's practise those words.

My turn, mass.

Your turn.

Lovely.

My turn, gramme.

Your turn.

Fantastic.

My turn, interval.

Your turn.

Fantastic.

So the mass is the word that we're gonna be using when we talk about how much matter something contains.

It's commonly measured by how much something weighs.

And one of the units that we are going to be using is called the gramme.

And I'm not sure if you can find one and ask an adult to find one for you, but if you can find a paper clip, that weighs about one gramme.

Now in maths, we like to abbreviate.

And so a gramme, instead of writing the word 'gramme', we can use a g, a lowercase G.

And that is in place of the word gramme.

It's an abbreviation.

So if you see the letter g, we mean gramme.

We're also going to be using the word intervals.

And these are the spaces between the numbers.

So if you see my scale here, you can see it's going up in 100s.

And the intervals are the spaces between the numbers that I've given you.

So the space between zero and 100, between 100 and 200, they are intervals.

They've all got, given numbers at the beginning and the end of each interval.

The lesson today is all about scales.

So we're going to start by looking at scales, which are marked in different ways.

We will then move on to think about problem solving using scales.

These are the children who are going to help us with our learning today.

We've got Aisha and Andeep.

So Andeep and Aisha want to bake a cake.

I wonder if you ever do any cake baking.

When you bake a cake, scales are used to measure the mass of ingredients.

Andeep finds the scales in his kitchen.

There's two scales he's managed to find.

And what do you notice about the scales? Hmm? Do you see anything that's the same or anything that is different? That's right.

Aisha has noticed that they're both measuring in grammes.

How can we tell they're measuring in grammes? That's right, they've got a little g towards the middle of the scale, and that tells us that the unit we are using here is grammes.

Ah, Aisha has also noticed that the last marked interval on one scale is 150.

Can you see that? And on the second scale is 800.

So that is something that is different about them.

One scale has interval of the 50, so it's counting up in 50s, zero, 50, 100, 150.

And the other has intervals of 200.

So zero, 200, 400, 600, 800.

So in their recipe, Andeep and Aisha need to use a 50 gramme egg.

Which of the scales do you think they should use to measure the mass of the egg? Which scale would you use? Hmm.

Andeep uses both scales with the same egg.

What do you notice? That's right.

Aisha is telling us that it's easier to know the egg is 50 gramme on the first scale because 50 gramme is marked.

On the second scale, that 50 gram's not marked, is it? So it would be a bit little bit harder to know that it's exactly 50 grammes.

Aisha decides to join in with the measuring.

She's found some different objects from the kitchen and she places them on those scales.

What do you notice? Is there something that's the same? Is there something that's different? That's right.

The arrows are pointing in the same direction on both scales, aren't they? Can you see that they're both pointing in the same direction? But I wonder if you've noticed what Andeep has noticed.

They are pointing to different numerical values because the scales are different.

So the arrows, even though they're pointing the same way, are pointing to different numbers.

The arrow on the first scale is pointing between 50 and 100 grammes, but on the second scale, it's just pointing to 400 grammes.

So the arrows were pointing the same direction, but they were pointing to different numbers.

So it's really important that we use the scale.

Let's look at some different scales.

What do you notice here? Hmm.

If I look at all my scales, what do you notice? What's the same about them and what is different? That's right.

Andeep has noticed the scales have different marked intervals.

The first scale, it's going up in 100s.

Second scale is going up in 500s.

The third scale in 200s.

And then the last scale is going up in 250s.

Did you notice that the arrows are all pointing to zero? But the zero is in different places.

So that's something really important that we need to notice when we use scales.

Let's look at this scale.

Do you notice that on the scale, the intervals are marked clockwise? So they go round in the direction that the clock hands move.

So the intervals are marked clockwise and it's important that we read scales in a clockwise manner.

And we can use this to help us work out unmarked intervals.

Ooh.

Andeep has spilt some flour on his scales whilst he was cooking.

What number is covered by the flour? Shall we work together to find out? Let's have a look.

100, 200, 300.

Ooh, what do you think is going to come next? What number has been covered by that flour? That's right, 400.

Now it's time to check your understanding so far.

Oops, Andeep spilt some flour on his scales whilst he was cooking.

What number is covered by the flour? Pause the video.

You might like to tell somebody what number you think it is.

See if they think the same.

And when you are ready, press play.

Okay, how did you get on? Did you notice that the scale was increasing in intervals of 100? And if we count round in 100, 100, 200, 300, 400, 500, 600, 700, the missing number is 800.

Well done.

And have a go at this one.

The same thing, what number is missing? Aisha is just prompting us to notice something.

What do we notice about those scales? Pause the video.

Have a go, seeing if you can identify which number is missing.

And when you are ready, press play.

Okay, how did you get on? Did you figure out which number was missing? That's right, 600.

This scale was counting up in 200s.

Hey, your turn to practise now.

We've got some scales here for task one.

Look at the scales.

The arrows have fallen off, oh dear.

Draw them where you think they should be.

So you've got three scales.

The first one wants you to draw an arrow showing 250 grammes, the second one, 400 grammes, and the third one, 500 grammes.

And for your second task, I would like you to have a look at these three scales.

Uh oh, some of the numbers are missing.

I wonder if you can label them and help me work out what they are.

But do stop and take care to notice what is the same and different about these scales before you get started.

Pause the video, and when you finish both tasks, press play.

Okay, how did you get on? The first one, you had to draw the arrows on where they should be because they had fallen off.

First one was that you were asked to draw an arrow to 250 grammes, 400 grammes for the second one, and then 500 grammes for the third one.

How did you get on? Well done.

For your second task, you were asked to find the missing numbers.

For the first scale, it was counting up in 200s, so the missing number was 800.

The second scale was counting up in 250s, so the missing number was 500, and the third scale was counting up in 100s, and the missing number was 900.

Did you spot that the zero was in a different place on that third scale? Let's move on now to the second part of our learning, problem solve using scales.

So let's look at this kitchen scale.

What can you say about the mass of the carrot? Hmm.

That's right, Aisha, the carrot is heavier than 100 grammes but it's lighter than 200 grammes.

How can we tell? That's right, because the numbers go clockwise and we can see the arrow has gone past the 100, but it has not got to the 200 yet.

Now we've got some cheese here with a different scale.

What can you say about the mass of the cheese? So let's have a think about, we know the intervals go clockwise and we know the arrow goes clockwise.

So what mass is it after and what's it before? That's right, Aisha.

The cheese is heavier than 400 grammes, but is lighter than 600 grammes.

And let's look at another different scale.

Uh oh, the arrow has fallen off.

Roughly, where would the arrow be for an orange that has a mass of 150 grammes? So we can see our scale.

The intervals are going up in 250 grammes, and the mass is only 150 grammes for the orange.

So it must be before the 250 grammes.

And Aisha agrees, she thinks it should go before the 250 grammes.

150 is smaller than 250.

And that's roughly where the arrow would be.

Let's check your understanding.

Look at this scale.

Aisha wants to measure the mass of a different household item.

She's found a basketball.

What can you say about the mass of the basketball? So have a think.

What has it got to be more than and what has it got to be less than? Pause the video.

And when you think you know, press play.

How did you get on? Did you notice that the basketball is heavier than 600 grammes because the arrow has gone past the 600, but it's lighter than 700 grammes 'cause the arrow hasn't got to the 700 yet.

Brilliant.

So look at this scale.

Roughly, where should the arrow be for a basketball that has a mass of 600 grammes? Do you notice now that the scale is slightly different? I want you to pause the video, maybe find someone to talk to and see if you can agree on roughly, where do you think the arrow should be pointing? Pause the video.

And when you are ready, press play.

How did you get on? That's right.

Did you agree with Aisha, who thinks it should go after the 500 grammes? Because 600 is more than 500, but before the 750 gramme mark, because 600 grammes is not as heavy as 750 grammes.

So the arrow should roughly be pointing in that direction.

So we can use scales to help us compare objects by their mass.

So have a look at these scales.

What do you notice? Which is heavier, the cheese or the orange? And how do you know? That's right, Aisha is telling us the cheese is heavier.

How does she know? Well, it's more than 400 grammes, that arrow has gone past the 400.

But the orange, the arrow hasn't even got to the 250 gramme mark yet.

So the cheese is heavier.

Let's check your understanding on this.

Which is heavier, the box for the shopping or the orange? Pause the video.

And when you think you know, press play.

How did you get on? The box is heavier.

Is that what you noticed? The box is nearly 500 grammes.

The orange is less than 250 grammes.

So the box is heavier.

Okay, it's your turn to have a go now.

For task B, question one, I'd like to look at these scales.

Uh oh, the arrows have fallen off.

Can you draw them roughly where they should be? The first scale, can you draw an arrow where 400 grammes would be? For the second, where 650 grammes would be? And for the third, where 200 grammes would be? For question two, could you start with the lightest? Put these objects in order of mass and then explain how you know.

So you've got the orange, the lemon, and the slice of watermelon.

So using the scales to help you, pop those objects in order of mass, starting with the lightest.

And for question three, can you look at these three scales? Which one shows the greatest mass? And can you explain how you know? You've got scales A, B, and C.

Remember to stop and think about what you notice about the scales first and see if that can help you.

Press pause on the video.

When you've done all three tasks, press play.

How did you get on? Should we have a look? For question one, you were asked to look at these scales and draw the arrows roughly where they should be.

For the first scale, you were asked to draw an arrow at about 400 grammes.

Well, that would be after 250, but before 500.

For the second scale, you needed to draw an arrow at 650 grammes.

That's right, that's halfway between 600 and 700.

And for the last one, you were asked to draw an arrow at 200 grammes.

That's right, it would not quite be halfway.

For question two, you were asked to put these objects in order of mass and tell me how you know.

So the lemon was the lightest, then the orange, then the watermelon.

And you might have told me that the mass of the lemon is less than 100 grammes, so it's the lightest.

The mass of the watermelon is more than 400 grammes and is the heaviest.

Well done.

And for your third question, you needed to look at these scales and think about which one shows the greatest mass and then tell me how you know.

So scale A shows the greatest mass because the arrow is pointing to a value that is nearly 750 grammes.

And the arrows on the other scales point to values at a less than 700 grammes.

So scale A must have the greatest mass.

Fantastic learning today.

We have become familiar with scales that have got different intervals when we're measuring in grammes.

We have learned that scales are marked with different intervals.

We know that when we use scales, we need to take care to look where the zero is marked and to notice those intervals.

We know that we can use scales to compare the mass of objects.

And we've learned that the mass of objects is measured in grammes.

So well done on your learning today.

Really impressed with how hard you have tried.

I'll see you again another time.

Well done.