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're 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 Compare and Order Measurements of Maths.

It comes from the unit Sense of Measure.

By the end of this lesson, you will be able to compare and order measurements of maths.

Remember that mass is a measurement of how heavy something is, so you're going to be thinking about things that are heavier or lighter today.

There are some key words that are going to help you in this lesson, so we're going to practise saying those now to get you ready.

I will have my turn first, and then it will be your turn.

Ready? My turn, lighter, your turn.

My turn, heavier, your turn.

My turn, lightest, your turn.

My turn, heaviest, your turn.

Well done.

Look out for those key words in this lesson today because they are really helpful for what you're going to be learning about.

There are going to be two parts to this lesson.

To begin with, you are going to learn about comparing and ordering using a balance, and then in a little while, you're going to compare and order measurements of maths.

Let's get started with compare and order using a balance.

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

Their names are Laura and Izzy.

Listen carefully to the things that Laura and Izzy have to tell you.

They've got lots of helpful things to tell you today that's going to help with what you're learning about.

Laura and Izzy are thinking about how they could compare the masses of two different objects.

They've got a notebook, and they've got a pencil case.

They could use a balance to find out which object is heavier and which object is lighter.

Let's see what that looks like.

They've placed the items on the balance, and we can see that the pencil case is heavier than the notebook.

The notebook is lighter than the pencil case.

Laura and Izzy are going to continue to compare the masses of different objects.

This time they have a pencil and an eraser.

You can see that the eraser is heavier than the pencil, and the pencil is lighter than the eraser.

Now they have a water bottle and a box of crayons.

This time the water bottle is heavier than the box of crayons and the box of crayons is lighter than the water bottle.

Let's check if you can see which item is heavier and which item is lighter on this balance scale.

Pause the video and have a go at filling in the gaps in those sentences.

Let's see if you've got it.

The unicorn toy is lighter than the playdough.

The playdough is heavier than the unicorn toy.

Well done if you got those the right way around.

Sometimes you might see different types of balances like these.

It's important to know that any type of balance can be used to compare maths.

The heavier object will be lower, and the lighter object will be higher.

Let's have a look at some of the objects that Laura and Izzy compared earlier.

We have the notebook, the pencil case, the water bottle, and the box of crayons.

Laura says we know which object on each balance is heavier, and Izzy is thinking about how we could find out which of these four objects is the heaviest.

So out of all four objects, Izzy wants to think about how you could find out which one is the heaviest.

I wonder if you've got any ideas.

Laura says it can't be the crayons or the notebook because they were the lighter object on each balance.

We know that it's either going to be the water bottle or the pencil case, which is the heaviest.

So, Izzy says we need to place the water bottle and the pencil case on the same balance.

Let's see what happens.

Now the water bottle and the pencil case are on the same balance, we can see that the water bottle is heavier than the pencil case.

That means that the water bottle is the heaviest of all four objects.

Which object do you think is the lightest? We know it can't be the water bottle, that's the heaviest.

We know it can't be the pencil case because the pencil case was heavier than the notebook, so it must be the notebook or the crayons.

We need to find out which one is the lightest by putting them on the same balance.

This time we can see that the crayons are heavier, so the notebook is the lightest object.

Laura thinks that now we can put them in order from heaviest to lightest.

We know the water bottle is the heaviest and we know the notebook is the lightest.

I wonder what's going to happen with the other two objects.

Oh, Izzy says wait, we need to compare the last two objects before we can put them all in order.

She's right, we don't know what order to put the crayons and the pencil case.

We need to put the crayons and the pencil case on the balance together and find out which one is heavier.

Now we can see the pencil case is heavier than the crayons, so if we continue with our order from heaviest to lightest, it will be the pencil case next and then the box of crayons.

Now we can see that all four objects are in order.

The water bottle is heavier than all the other objects.

The notebook is lighter than all the other objects.

The pencil case is heavier than the crayons but lighter than the water bottle, and the crayons are heavier than the notebook but lighter than the pencil case.

Let's check if you can order objects by their mass using a balance scale.

Listen to each sentence carefully and think about what the missing word could be.

The Mmm is the heaviest.

The Mmm is the lightest.

The pencil case is than the beanbag, but Mmm than the book.

Pause the video and have a think about how you could complete those sentences.

Good thinking! Let's have a look.

The book is the heaviest.

The beanbag is the lightest.

The pencil case is heavier than the beanbag but lighter than the book.

Well done if that's how you completed those sentences.

Good job! Now it's time for you to practise comparing masses using a balance.

First, you need to choose two objects and place them on a balance.

Then you are going to say these sentences with the name of each object in the correct place.

The Mmm is heavier than the Mmm and the Mmm is lighter than the Mmm.

Next, you're going to choose three or four objects and then choose two at a time to place on your balance.

This time you're going to see if you can put them in order from the lightest to the heaviest.

You could use these sentences in the box to help you.

The Mmm is heavier than the Mmm but lighter than the Mmm.

The Mmm is heavier than all the other objects so it's the heaviest.

The Mmm is lighter than all the other objects, so it is the lightest.

It's time for you to pause the video and have a go at those now.

Off you go! Well done, everybody! Let's have a look and see how you got on.

These are the objects that Laura and Izzy chose.

They had a stone and a stick.

They could say that the stick is lighter than the stone and the stone is heavier than the stick.

Then they found a different type of balance and they chose a building block and a car.

They said, the building block is lighter than the toy car and the toy car is heavier than the building block.

I wonder if you chose objects like this, or if yours were different? Did you remember to look at the balance to see which item was heavier? Well done if you did! Now let's have a look at the second question.

If you chose these objects, this is how you could have completed the sentences and then put the objects in order from lightest to heaviest.

You could say the toy car is heavier than the building block but lighter than the stone.

You could also say that the building block is heavier than the stick but lighter than the toy car.

You could say that the stone is heavier than all the other objects, so it is the heaviest and the stick is lighter than all the other objects, so it is the lightest.

Then we could put them in order knowing that the stick is the lightest, then the building block, then the toy car, and then the stone.

Well done if you were able to use your balance to check which items were heavier or lighter and then to be able to put them in order from the lightest all the way to the heaviest.

Now it's time for the second part of this lesson where you're going to be thinking about comparing and ordering measurements of mass.

Let's have a look at that now.

Laura says in science last week I found out that a grey wolf has a mass of 40 kilogrammes.

I wonder if you've ever learned about the mass of any other animals in any of your science lessons.

That sounds very interesting.

Izzy says that we could write that using the letters kg to show kilogrammes so we could say a grey wolf has a mass of 40 kilogrammes.

Laura says I have a toy wolf, let's measure its mass with some scales.

She's going to put the toy wolf on the scales, and we can see that the black arrow is pointing to 40.

Izzy says the toy wolf is 42.

They must have the same mass.

Oh, what do you think? Would a toy wolf and a real wolf have the same mass? I wonder if they've forgotten to look at something.

Laura says it doesn't seem right, let's check the scales again.

Oh, Izzy has noticed it now.

This scale measures in grammes, not kilogrammes.

We can write g to show grammes.

A toy wolf has a mass of 40 grammes.

Now we can compare these measurements of mass.

The toy wolf is lighter than the real wolf.

The real wolf is heavier than the toy wolf.

We could also say 40 kilogrammes is greater than 40 grammes and 40 grammes is less than 40 kilogrammes.

We could also use symbols to compare these measurements of mass.

40 kilogrammes is greater than 40 grammes and 40 grammes is less than 40 kilogrammes.

Let's check that you can compare these measurements of mass.

This time we know that a toy pig has a mass of 80 grammes and a real pig has a mass of 80 kilogrammes.

You need to have a think about what could be missing from each box to be able to compare these measurements of mass.

Pause the video and think about what could go inside each box.

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

We can say that the real pig is heavier than the toy pig.

80 grammes is less than 80 kilogrammes, and 80 kilogrammes is greater than 80 grammes.

Then we could use our inequality symbols to say that 80 grammes is less than 80 kilogrammes, and 80 kilogrammes is greater than 80 grammes.

Well done if that's how you filled in each box.

Good job.

You have seen that when the numbers are the same, you can use the unit of measure to compare mass.

Now Laura's thinking I wonder how we could compare mass when the unit of measure is the same, but the numbers are different, so what if both measurements are in grammes or both of them are in kilogrammes.

Izzy says that we should think about what we've learned before about comparing and ordering numbers.

Let's have a look at that now.

We know that you can represent numbers with base 10 blocks and that can help you to compare numbers.

We have the numbers 42 and 29.

Which number is greater? That's what we're going to think about now.

Laura wonders how we could find out which number is greater by looking at this base 10 equipment.

Izzy knows that tens are greater than ones, so she says that we should compare the tens.

42 has more tens than 29.

That means that 42 is greater than 29 because it has more tens.

Izzy can remember a different strategy to compare and order numbers.

Izzy thinks of a number line to help her compare and order numbers.

She knows that 42 is greater than 29 because it comes later in the counting sequence.

That means that when she counts to 42, she counts past 29 so 42 must be greater.

We can see on the number line that 29 is here and 42 is here, so 42 is greater than 29 because it comes further along the number line.

29 is less than 42 because it's not as far along the number line.

Izzy chooses another number so that she can write them all in order starting with the smallest.

Izzy chooses the number 17.

We can see 17 on the number line here.

Izzy says, I can see that 17 comes before the other numbers on the number line.

That means that 17 will be the first number when you write them in order starting with the smallest.

It would be 17, then 29, and then 42.

We could show that using symbols by writing 17 is less than 29 and 29 is less than 42.

Now Izzy is going to choose a different number.

She's going to keep 29 and 42 but she's going to choose a different number so that she can put them in order.

This time she chooses 51.

We can see 51 here on the number line.

Izzy says I can see that 51 comes after the other numbers on the number line.

Laura says that means that 51 will be the last number that you write when you write them in order starting with the smallest.

So, the order will be 29, then 42, and then 51.

If we wanted to write that using symbols, we would say 29 is less than 42 and 42 is less than 51.

Now Izzy is going to choose another different number.

She's keeping 29 and 42 but this time she's going to choose the number 34.

We can see 34 on the number line and Izzy can see that 34 is between 29 and 42 on the number line.

Laura says that means that 34 will be the second number when you write them in order starting with the smallest.

The order will be 29, 34, 42.

If we wanted to write that using symbols, we need to say that 29 is less than 34 and 34 is less than 42.

You could also use a table like this to help you order numbers.

If we have the numbers 56, 71, and 60 and we want to put them in order from the smallest to the greatest, we could think about how many 10s and how many 1s are in each number.

56 is five 10s and six 1s.

71 is seven 10s and one 1.

60 is six 10s and no 1s.

Izzy knows that 10s are greater than 1s so the number with the fewest 10s will be the smallest number.

Let's have a look at the 10s: 5, 7, and 6.

5 is the fewest number of 10s that means 56 is the smallest number.

Now we need to look at the two numbers that are left.

I can see that one has seven 10s and one has six 10s.

Six is the fewest number of 10s left so that means that 60 will be the next number and 71 is the greatest number.

You can see how using a table to look at the number of 10s and the number of 1s can be a really helpful way of thinking about putting numbers in order.

You have just thought about the different ways that you can compare and order two-digit numbers.

When you want to compare and order measurements of mass, you can do this in exactly the same way that you can compare and order two-digit numbers.

So, let's have a look at some masses and see how we could compare them.

The mass of a lion is 94 kilogrammes.

We could use a table and look at the number of 10s and 1s.

94 has nine 10s and four 1s.

The mass of a cheetah is 58 kilogrammes.

58 has five 10s and eight 1s.

If we want to compare these two masses, Laura knows that nine 10s is greater than five 10s so 94 kilogrammes is greater than 58 kilogrammes.

Izzy says I could compare these masses by saying that the lion is heavier than the cheetah.

We could also show this using a symbol.

We could say 94 kilogrammes is greater than 58 kilogrammes.

Let's have a look at another example.

This time we have three masses.

These are the masses of fruit.

We have a plum, a strawberry, and a satsuma and this time we're going to think about using a number line to help us order them.

We can see that the plum has a mass of 55 grammes, the strawberry has a mass of 48 grammes, and the satsuma has a mass of 62 grammes.

We can label each mass on our number line.

Now we can see that 62 grammes is the heaviest mass because it is the furthest number along the number line.

We can say that 62 grammes is greater than 55 grammes.

We know that 48 grammes is the lightest mass because it comes before all the other measurements on the number line so that means that 55 grammes is greater than 48 grammes.

Let's check if you can order these masses.

This time we have a carrot, a spring onion, and a tomato.

Have a think about how you might be able to order these masses.

Pause the video and have a go at that now.

Let's see what you were thinking about the order of these masses.

We could say that the spring onion is the lightest food because 16 has one ten which is the fewest amount of tens.

We could say that the tomato is the heaviest food because 86 has the greatest amount of tens.

We could put all the foods in order starting with the heaviest.

We could say the tomato is the heaviest and then the carrot and the spring onion is the lightest or we could put them in order starting with the lightest so we would say the spring onion is the lightest and then the carrot and then the tomato is the heaviest.

We could also write them using symbols.

We could say that 86 grammes is greater than 61 grammes and 61 grammes is greater than 16 grammes.

We could write those the other way around.

We could say 16 grammes is less than 61 grammes and 61 grammes is less than 86 grammes.

You could also have used a number line or a table to help you to compare and order these masses.

Now it's time for you to practise comparing and ordering measurements of mass.

To begin with, you're going to choose a phrase from the box to compare each pair of masses.

You need to choose lighter than, heavier than, or the same as for each sentence.

Next, you're going to use symbols.

You need to write a greater than or a less than symbol in each box to show how you would compare each pair of masses.

Laura and Izzy have some helpful hints for you here.

Laura says remember to look carefully at how many tens are in each number, and Izzy says don't forget to check the unit of measure for each mass.

Next, you're going to have a look at Izzy's information that she collected when she went to the zoo.

She found out the masses of some different animals.

She looked at a capybara, a chimpanzee, a hyena, a porcupine, and a wombat.

What you need to do is look at the mass of each animal and see if you can write the names of the animals in order of their mass starting with the heaviest.

You could use a number line, or you could use a table to help you look at how many tens are in each number but you're going to write the names of the animals in order starting with the heaviest.

Once you've done that, you're going to look at the table again but this time you're going to write the masses in order not the names of the animals.

You're also going to use greater than or less than symbols to show the order of the masses.

Laura says, that you might be able to find more than one way to write the masses in order using symbols.

Finally, you're going to have a think about this.

Izzy learned the mass of one more animal, the sun bear, and she knows that a sun bear is heavier than a chimpanzee but lighter than a capybara.

What could the sun bear's mass be? Izzy says, that there is more than one answer.

How many different answers can you find for this? You're going to pause the video and have a go at that work now.

Off you go.

Okay, let's see how you got on.

First, you needed to choose a phrase to compare each pair of masses.

You should have 60 kilogrammes is heavier than 60 grammes, 14 grammes is lighter than 14 kilogrammes, 52 kilogrammes is the same as 52 kilogrammes, they've just written kg for short, 5 kilogrammes is heavier than 5 grammes, 40 kilogrammes is heavier than 40 grammes, and 16 grammes is lighter than 16 kilogrammes.

Well done if you filled those in correctly.

Next, you needed to use a greater than or a less than symbol in each box to compare these masses.

37 kilogrammes is less than 73 kilogrammes, 19 kilogrammes is less than 91 kilogrammes, 69 grammes is less than 72 grammes, and 43 kilogrammes is greater than 29 kilogrammes.

For all of those first four questions, you needed to think about what Izzy is saying.

If the unit of measure is the same, then the number with more tens will be greater.

When you got to the next question, you might have noticed something different.

This time the numbers were the same so Laura has remembered that when the numbers are the same the unit of measure can help you to compare masses.

71 kilogrammes is greater than 71 grammes.

50 kilogrammes is less than 60 kilogrammes.

25 grammes is less than 55 grammes, and 6 grammes is less than 6 kilogrammes.

Well done if you've got those correct.

Now let's have a look at the masses of these animals.

First, you needed to write the names of the animals in order of their mass.

You might have used a number line to help you.

The capybara was 54 kilogrammes.

You could label that on your number line.

The chimpanzee was 45 kilogrammes, the hyena was 60 kilogrammes, the porcupine was 24 kilogrammes, and the wombat was 32 kilogrammes.

Now that all those masses are on the number line, I can see that 60 kilogrammes is the heaviest mass.

That means the hyena must be the heaviest animal.

Then it's the capybara, then the chimpanzee, then the wombat, and the porcupine is the lightest animal.

Well done if you've got those animals in the correct order.

Next, you needed to write the masses of the animals in order using the symbols to show which order you've put them in.

You could choose to start with the heaviest or the lightest, but you needed to make sure that you've got your symbols correct to show the order.

So, you could say that 24 kilogrammes is less than 32 kilogrammes, which is less than 45 kilogrammes, which is less than 54 kilogrammes which is less than 60 kilogrammes.

Or you might have chosen to start with the heaviest and use the greater than symbol.

Well done if you found both ways to show the order of those using symbols.

Finally, we needed to think about the mass of the sun bear.

We know that it's heavier than the chimpanzee but lighter than the capybara.

So, what would be really helpful is if we labelled where the chimpanzee's mass and where the capybara's mass are on our number line.

The chimpanzee would be here, and the capybara would be here.

Now we know that the sun bear must be on one of these points between the chimpanzee and the capybara.

That means that the mass of the sun bear could be 46 kilogrammes, 47 kilogrammes, 48 kilogrammes, 49 kilogrammes, 50 kilogrammes, 51 kilogrammes, 52 kilogrammes, or 53 kilogrammes.

Well done if you found all of those different possible masses.

Good job.

Now that you're at the end of the lesson, you know that when you compare mass, you are finding which mass is heavier or lighter.

When you order mass, you find which mass is the heaviest or the lightest, and you can show a set of masses in order.

You can start with the heaviest or the lightest mass.

When the numbers are the same, you can use the unit of measure to compare mass.

When the units are the same, you can compare and order mass in just the same way that we would compare, and order two-digit numbers.

You also know that you can use greater than and less than symbols to compare and order mass.

You have done some really excellent thinking today about comparing and ordering measurements of mass.

Well done.

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

Bye everyone.