Lesson video

Hello, everybody.

My name is Mrs. Johnson.

I am so happy to be here today to help you with some of your maths learning.

I hope you are ready to work hard and have lots of fun as we learn new things.

Let's have a look at what we're going to be learning about today.

This lesson is called explain why standard units are needed.

It comes from the unit sense of measure.

By the end of this lesson, you will be able to explain the difference between standard and non-standard units of measure, and you will be able to explain why we need standard units of measure.

There are two key words in this lesson.

We're going to practise saying them now.

My turn first and then your turn.

Ready? My turn.

Unit of measure.

Your turn.

My turn.

Standard unit.

Your turn.

Well done.

Listen carefully for those words today because they are really important for your learning in this lesson.

There are going to be two parts to this lesson.

To begin with, we're going to think about measuring using different units, and then in a little while, we're going to be learning about standard units.

Let's get started with measure using different units.

There are two friends who are going to help in this lesson today.

Their names are Jun and Aisha.

Listen carefully to the things that Jun and Aisha have to tell you because they are going to be really helpful for your learning today.

Jun and Aisha want to measure this pebble that they found.

Aisha says, "I could use building blocks to measure its length." One, two, three, four.

"The pebble is four blocks long." Aisha can measure the length of the pebble.

Jun says, "I could use building blocks to measure its width." One, two.

He says, "The pebble is two blocks wide." They've both used building blocks to measure the length and the width of the pebble.

Aisha has thought of another way that she could measure this pebble.

She says, "I could use building blocks to measure how heavy the pebble is." She can use a balance like this.

They're going to place blocks inside the empty bucket until the buckets balance.

One, two, three, four, five, six, seven, eight, nine, and now the buckets have balanced.

This pebble is as heavy as nine building blocks.

Jun and Aisha chose building blocks as their unit of measure to measure how heavy the pebble is, so they've measured the length, they've measured the width and they've measured how heavy the pebble is all using building blocks.

Jun says, "Let's find something else that we could measure." I wonder what they're going to find next.

They've got some sunglasses.

Aisha says, "This time we could use paperclips to measure the length." One, two, three, four.

The sunglasses are four paperclips long.

Jun says, "I could use paperclips to measure the width." One.

"The sunglasses are one paperclip wide." Jun and Aisha chose paperclips as their unit of measure to measure the length and the width of the sunglasses.

Aisha says, "I could use paperclips to measure how heavy the sunglasses are." She's going to use the balance again.

They're going to place paperclips inside the empty bucket until the buckets balance.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and now the buckets balance.

These sunglasses are as heavy as 16 paperclips.

Jun and Aisha chose paperclips again as their unit of measure to measure how heavy the sunglasses are.

Jun says, "Do you think that we could use any object as our unit of measure?" They've used building blocks and they've used paperclips.

Could they use any object? I wonder what you think.

Let's see what Aisha thinks.

Yes, any object can be a unit of measure as long as they are all identical.

Paperclips and building blocks are always the same size, so they are good things to choose as a unit of measure.

You can't choose things that might be different sizes, but any object, as long as they are identical, can be a unit of measure.

Let's check if you know how to use objects as a unit of measure.

You're going to look carefully at these pictures and decide which sentences are correct.

The toy car is nine dominoes long.

The toy car is as heavy as nine dominoes.

The toy car is five dominoes long.

The unit of measure is dominoes.

Pause the video and have a think which of those sentences are correct.

Let's have a look and see how you got on.

The toy car is as heavy as nine dominoes.

That's true.

If you look at the balance, you can see that the two buckets are balanced.

There is one toy car on one side and nine dominoes on the other side, so sentence B is true.

The toy car is five dominoes long.

That's true.

You can see that there is a straight line of dominoes underneath the car and there are five dominoes in that line, so the car is five dominoes long.

That's true.

And D, the unit of measure is dominoes.

That's true as well.

That's the object they've chosen as the unit of measure.

The only sentence that was not true was A.

The toy car is not nine dominoes long.

It's five dominoes Long.

Well done for thinking carefully about that.

Now, it's time for you to practise measuring using different units of measure.

You're going to choose some objects from around you that you would like to measure.

Then you are going to choose your unit of measure.

Make sure that it's something that is always identical, something like paperclips or dominoes or building blocks.

You're going to write your objects and your measurements on the table.

Make sure that for each measurement you write the unit of measure as well.

Pause the video and have a go at that now.

Excellent measuring, everybody.

Well done.

Let's have a look how you got on.

You might have filled in your table a little bit like this.

I chose a pencil and eraser and some scissors as my objects.

The pencil was five paperclips long and it was as heavy as 10 paperclips.

The eraser was two dominoes long and it was as heavy as five dominoes.

The scissors were six building blocks long and they were as heavy as 11 building blocks.

Did you remember to write the unit of measure that you chose each time you wrote a measurement? Well done if you did.

Good job.

Now, it's time for the second part of our lesson.

We are going to learn about standard units.

You're going to listen to a story.

This is a story all about a panda called Pedro and his quest to get his friend a birthday present.

"Pedro was excited.

It was almost his good friend Sydney the Snake's birthday.

He wanted to get him a very special present.

Pedro decided to get Sydney a bed.

Sydney didn't have a bed of his own and Pedro thought this would be the perfect gift.

Pedro wanted the bed to be the right size for Sydney, so he measured Sydney by walking carefully in a straight line from his head to his tail.

Pedro counted his footsteps.

'Sydney will need a bed that is nine footsteps long,' Pedro said to himself.

Pedro asked his friend Freda the Fox to look in the forest to find some pieces of wood that were nine footsteps long.

Freda walked carefully in a straight line from one end to the other to make sure each piece of wood was nine footsteps long.

Freda passed the pieces of wood to Claire the Cat since she had a talent for making things.

'Make sure the bed is nine footsteps long,' Freda told Claire.

Claire joined the pieces of wood into a bed that was nine footsteps long.

On the day of Sydney's birthday, Claire brought the bed to Pedro.

Pedro was so excited to give Sydney his gift.

He tied a bow onto the bed with some ribbon and waited for Sydney to arrive.

When Sydney arrived, Pedro couldn't wait to give him his gift.

'Lie on the bed, Sydney!' Pedro excitedly told his friend.

But when Sydney lay down, Pedro was so disappointed.

The bed was too small.

'How did this happen?' Pedro asked himself.

'I made sure the bed was nine footsteps long,' said Claire.

'I made sure the wood was nine footsteps long,' said Freda.

'Whose footsteps did you use to measure the bed?' Sydney asked his friends.

'We each used our own footsteps,' the friends replied, 'But your footsteps are different sizes!" Sydney giggled.

'When Pedro measured Sydney, he was nine footstep long.

I should have collected pieces of wood that were nine Pedro-footsteps long,' Freda realised.

'I should have made a bed that was nine Pedro-footsteps long,' Claire exclaimed.

Once Freda and Claire realised what had happened, they knew what to do.

They drew around Pedro's foot and cut out his footprint.

Freda took Pedro's footprint with her to find more wood that would be the correct length.

Then Claire used Pedro's footprint to join the pieces of wood together into a bed that would be the right length.

Claire and Freda took the bed back to Pedro and Sydney.

They couldn't wait to show their friends the new bed they had made.

As soon as Sydney lay on the new bed, all his friends cheered.

It was the perfect fit.

Hooray! 'Thank you so much for my new bed.

It is the best birthday present I've ever had,' Sydney told his friends." What a lovely story.

That was great, wasn't it? Jun says, "I felt sorry for Pedro when he realised the bed was too small for Sydney." And Aisha says, "Did you notice that Pedro, Claire, and Freda all used different units of measure?" They all used different footsteps or footprints, didn't they, as their unit of measure.

When Pedro, Freda, and Claire each measured length using their own footsteps, they were using different units of measure.

When they all used Pedro's footprint to measure, they were all using the same unit of measure.

Jun says, "That means that if we choose the same unit of measure, we will get the same result." Aisha says, "It could be difficult to always have to talk about your unit of measure before you can start measuring." Jun says, "That is why we have standard units of measure." A standard unit of measure does not get larger or smaller.

It will always be the same size.

Standard units of measure are used in different countries all over the world, and they are always the same size.

Aisha says, "I think I can remember a standard unit of measure that I've used before.

A centimetre is a standard unit of measure." I wonder if you remember learning about centimetres before.

A centimetre is a standard unit of measure for length.

Who has used a standard unit of measure here? Let's check if you can identify the standard unit of measure.

Pause the video and have a think.

Well done.

Good thinking, everybody.

Jun says, "The astronaut is 11 blocks tall." And Aisha says, "The astronaut is eight centimetres tall." They've both measured the height, but Aisha has used centimetres as her unit of measure.

Centimetres are the standard unit of measure.

Blocks are not a standard unit of measure.

Different people might have different sized blocks and so they would not always get the same result.

Everybody who uses centimetres will get the same result because a centimetre is a standard unit.

That means it will not get bigger or smaller.

A centimetre is always the same size.

Now, you are going to go and do a piece of work that's going to help you think about standard units of measure.

These units of measure are about one centimetre.

The width of a paperclip is about one centimetre and the width of a thumbnail is about one centimetre.

These are not standard units, but we could use them as a unit of measure.

You are going to use these units of measure to try and draw a line that is about 10 centimetres long.

You're not allowed to use a ruler.

You have to use the width of a paperclip or the width of a thumbnail and have a go at drawing a line that you think is about 10 centimetres long.

Then you are going to compare the line that you have drawn to this printed line, which is exactly 10 centimetres long, and think about what you notice.

Once you've had a look at the line that you drew and the printed line, see if you can explain why it is helpful to use standard units of measure.

Pause the video and have a try at that now.

Well done, everybody.

Let's see how you got on.

Maybe you did your work a little bit like Aisha.

She says, "I used paperclips to help me draw this line that is about 10 centimetres long." And Jun says, "I used my thumbnail to help me draw this line that is about 10 centimetres long." When you compare Jun and Aisha's lines to the line that was printed, you can see that they're not exactly the same length.

Aisha's line is a little bit shorter and Jun's line is a little bit longer.

Aisha and Jun's lines are not exactly 10 centimetres in length because they didn't use a standard unit of measure.

I hope that you realised that standard units of measure are really useful because they will always give exactly the same size and they will give an accurate measurement.

That's why standard units of measure are really helpful.

Well done if you thought about that.

Now that you are at the end of this lesson, you have learned that you can use any identical object as a unit of measure.

And you know that when you use different units of measure, you will get different results.

If you use the same unit of measure, you will get the same result.

Standard units of measure are useful because they are always the same size and they do not change.

They can be used in different countries all over the world.

Centimetres are an example of a standard unit.

Well done for lots of excellent thinking today all about units of measure and standard units.

You've worked really hard.

Good job, everybody.

I hope that I will see you again soon for some more maths learning.

Bye, everyone.