Lesson video

Hello there.

My name is Miss Coe and I'm really looking forward to learning with you in this unit all about place value.

I know that you are going to really enjoy these lessons and work really, really hard to deepen your understanding.

So if you're ready, let's begin.

So, the outcome of our lesson today is that you will be able to find multiples of 10 that total 100.

Our key words for this lesson today are compose and multiple.

I'm going to say those words and I would like you to say them back to me.

My turn.

Compose.

Your turn.

Great job.

My turn.

Multiple.

Your turn.

Well done.

Let's have a look and see what those words mean.

So you can compose larger numbers from smaller numbers.

You might already know that 100 can be composed in lots of different ways using smaller whole numbers.

So you might know that 100 can be composed from 10 tens.

We can also compose 100 from multiples of 10, and we'll be thinking about that today.

A multiple is the number that you get when you multiply a certain number by an integer.

Lesson today is in two parts.

We're going to start by thinking about how 100 is composed of 10, and then we're going to think about applying our number bonds to 10.

Let's get started about thinking about how 100 is composed of tens.

In this lesson today, you're going to meet Andeep, Jacob, and Izzy.

They are going to be helping you with your learning, but they're also going to ask you some tricky questions to help you deepen your understanding.

Let's get started.

Now, you may already be familiar with the idea that 100 is composed of 10 tens.

We can show this by using tens counters in a tens frame.

So we have 10, 10 counters.

Each of those represents 10.

And because it's in a tens frame, there are 10 of them.

Let's check by counting in tens up to 100.

So we're going to start our count at 10 and we count.

10, 20, 30, 40, 50, 60, 70, 80, 90, 100.

Great job.

So we can see clearly that 10 tens make 100.

We can also represent this as single tens.

So this bar model shows that 100 is composed of 10 tens, but this time we've written 1 ten rather than the numeral 10.

Each part of the bar still represents 10.

So let's try counting backwards from 100 to 0, but this time we're going to count in tens.

So our first number is going to be 10 tens.

Are you ready? Let's go.

10 tens, 9 tens, 8 tens, 7 tens, 6 tens, 5 tens, 4 tens, 3 tens, 2 tens, 1 ten, 0.

Great job.

Well done.

So, we know that 100 is composed of 10 tens and we can show this in different ways.

So these are some of the representations we're going to use in this lesson.

We can now start to think about different ways that 100 can be composed.

So this tens frame shows that 100 can be composed of 1 ten and 9 tens.

We can see that there is 1 ten in one group and then 1, 2, 3, 4, 5, 6, 7, 8, 9 tens that are shaded.

100 can be composed of 1 ten and 9 tens.

We can show this as a bar model.

So the top bar shows our hole, which is 100, and then we have 1 ten unshaded and 9 tens shaded.

So this still shows that 100 can be composed of 1 ten and 9 tens.

We can also write this as an addition.

So we can say that 1 ten plus 9 tens is equal to 10 tens and we know that 10 tens are equal to 100.

100 can be composed of 2 tens and 8 tens.

So here we have an unshaded parts of 2 tens and a shaded parts of 8 tens.

And again, we can show that on a bar model.

We have a shaded parts of 8 tens and an unshaded parts of 2 tens.

So we can say that 100 can be composed of 2 tens and 8 tens.

Let's say that together.

100 can be composed of 2 tens and 8 tens.

Well done.

So we can also say that 2 tens plus 8 tens is equal to 10 tens.

10 tens as we know makes 100.

Oh.

100 can be composed of 3 tens and 7 tens.

So here I can see 3 unshaded tens and 7 shaded tens.

I think I might be starting to see a pattern here with the tens that we've been adding to make 100.

Hmm, I wonder if you can spot it.

So we can say that 3 tens plus 7 tens is equal to 10 tens.

100 can be composed of 4 tens and 6 tens.

So we have 4 unshaded tens and 6 shaded tens and we can write 4 tens plus 6 tens is equal to 10 tens, which is 100.

100 can be composed of 5 tens and 5 tens.

I can definitely see a pattern now.

Can you? We are 5 unshaded tens and 5 shaded tens.

So we can write that 5 tens plus 5 tens is equal to 10 tens.

Andeep shows these relationships using bar models.

So here we can see lots of different ways that 100 can be composed of tens.

We've got 1 ten and 9 tens make 100.

2 tens and 8 tens make 100, and so on.

Just take a moment to have a look at those bar models.

What do you notice about them? Can you notice any patterns or anything else? Hmm.

Well, Andeep says that some of these just show the same parts but in a different order.

So if we look at the top two bar models, the first one says 100 is equal to 1 ten plus 9 tens, and the other one says 100 is equal to 9 tens plus 1 tens.

And we know that we can swap those parts around and they'll still mean the same thing.

So we know that we can add 1 ten and 9 tens or 9 tens and one tens and they'll still make 100.

So we're gonna get rid of those.

We don't need to repeat ourselves.

So we can now see that there are five ways of making 100 on this screen.

Andeep's noticed something else.

He says, "When one part increases by 1 ten, the other decreases." Hmm, let's have a look at that.

Our first bar model shows 1 ten and 9 tens.

Our second bar model shows 2 tens and 8 tens.

So my first part increases by 1 ten and then we've gone from 9 tens to 8 tens.

Ooh, Andeep might be right.

That's a decrease of 1 ten.

Let's look at the next bar model.

So we had 2 tens and 8 tens.

Now, we've got 3 tens and 7 tens.

Oh, I think you might be right.

Our first parts has gone from 2 tens to 3 tens.

It has increased by 1 ten.

So our second part has gone down.

It was 8 tens and now it's 7 tens.

It's gone down by 1 ten.

Andeep is absolutely correct.

When one part increases by 1 ten, the other part decreases by 1 ten.

Well spotted, Andeep.

Time to check your understanding.

You have three images here labelled a, b, and c.

Take a good look at them and decide which of the images shows 100 composed of 4 tens and 6 tens.

Pause the video here and have a go.

How did you get on? Well, actually, you should have spotted two images I was trying to trick you.

A is a bar model.

And we can see that there are 6 tens shaded and 4 tens unshaded.

So we have 6 tens and 4 tens or 4 tens and 6 tens, which make 100.

C is 100 square and there are 4 tens shaded and 6 tens unshaded.

So 4 tens and 6 tens make 100.

B.

Oh, b could nearly be 4 tens and 6 tens.

I can see 4 tens on the top row shaded, but then I've got one additional 10 on the second row that shaded.

So that means there are 5 tens and 5 tens, not 4 tens and 6 tens.

Well done if you spotted that.

He says, what if his bar model didn't have two parts, but what if it had three parts? Well, I think that's a very tricky challenge, Andeep.

I'm sure Izzy would be able to rise to it.

So let's think about this bar model.

This means that 100 is split into three parts.

We don't know what any of those parts are, but we know that 1 ten plus 9 tens is 100.

2 tens plus 8 tens is 100, and so on.

So what if we had three parts instead? Hmm.

So, Izzy is going to use her tens frame to help her.

She needs to make three parts and she knows that 100 is composed of 10 tens.

So she decides to make one part of 2 tens.

So here she has her one part of 2 tens and then she's got one part of 8 tens there.

Hmm, so she hasn't quite met Andeep's challenge yet because she has two parts.

Okay, so let's make another part.

So then Izzy is making a different parts of 3 tens.

So she now has three parts, doesn't she? She has one part of 2 tens, one part of 3 tens, and then one part, the leftovers, which is 5 tens.

The third part is 5 tens.

I think Izzy might have met Andeep's challenge.

She can then show this on a bar model.

100 can be composed of 2 tens, 3 tens, and 5 tens.

We can see that we have 10 tens altogether, which we know makes 100, and this time we have three parts, 2 tens, 3 tens, 5 tens.

Well done, Izzy, because you have met Andeep's tricky challenge.

Izzy has shown a different way on the bar model, so she's gone even further and met Andeep's challenge twice.

She says that 100 can also be composed of 2 tens, 2 tens, and 6 tens.

Have a quick count up.

Are there still 10 tens altogether? Yes, there are.

So we can say that 2 tens plus 2 tens plus 6 tens is equal to 10 tens.

So we have three parts that make 100.

Well done, Izzy.

Time to check your understanding.

So Andeep has shown Izzy's two different answers in bar models.

So we can see that her first answer, 2 tens plus 3 tens plus 5 tens, and her second answer, 2 tens plus 2 tens plus 6 tens.

Andeep is now challenging you.

Can you find a different way to compose 100 of three parts? Pause the video and have a go.

How did you get on? You may have realised that there's actually more than one way to do that.

If you have a partner, you might want to see if they have the same way that you did it.

So some possible answers are now on the screen.

You could have said 1 ten plus 4 tens plus five tens makes 100.

So 100 can be composed of three parts of 1 ten, 4 tens, and 5 tens.

He might have said 100 is made of 7 tens, 1 ten, and 2 tens.

There are lots of different ways, but remember you need 10 tens altogether to make 100.

So if you've got 10 tens in three parts, then well done.

You have also met Andeep's challenge.

Time for your first practise task.

For the first part, I would like you to fill in the blanks to describe how 100 is composed in these tens frames.

So if we look at the first example, you've got some shaded and unshaded counters that represent tens.

So we can say that mm tens plus mm tens is equal to 10 tens.

You will need to fill in the blanks for each example.

And then for your second question, a bit more tricky.

We now know that 100 can be composed of mm tens and mm tens.

We also know that 100 can be composed of mm tens, mm tens, and mm tens.

So three parts.

Use the stem sentences to describe different ways that 100 can be composed from tens.

Use the bar model to see if you can find lots of different ways.

Pause the video now and have a go at those two tasks.

How did you get on? These are the answers for part one of your task.

Pause the video and have a look and give yourself a tick if you got all of these.

Now, for task two, there are lots of different ways that you could have completed these sentences, so let's just think about a couple of them.

I can see 1 ten and 9 tens composing 100.

So we know that 1 ten and 9 tens makes 10 tens, which is 100.

You might have also said, I can see 7 tens and 3 tens composing 100.

For three parts, you might have said, I can see 3 tens, 3 tens, and 4 tens composing 100.

There are lots and lots of different ways to complete these sentences, so well done if you found lots of different ways to do that.

Great job.

Let's move on to the second part of our lesson where we're thinking about our number bonds to 10.

So we already know that we can compose 100 from two different parts.

These models show that 3 tens and 7 tens are equal to 10 tens or 100.

So we can see that there are 3 shaded tens, 7 unshaded tens, and that they make 100.

These are different representations of the same idea.

You can also describe this using multiples of 10.

So we know that 3 tens and 7 tens make 100.

We also know that 3 tens, we can say that as 30, and 7 tens can be said as 70.

So we can also say that 30 and 70 make 100.

30 and 70 are both multiples of 10.

So we can say that 100 can be composed of 3 tens and 7 tens, but we can also say that 100 can be composed of 30 and 70.

It's just slightly different language to say the same thing.

Andeep has spotted a relationship and he is shown that using two bar models.

Take a look at the bar models.

I wonder if you could already see the relationship that Andeep is going to tell us.

So Andeep is saying, "I know that 3 plus 7 is equal to 10, so 3 tens plus 7 tens is equal to 10 tens and we can also say that 30 plus 70 is equal to 100.

So he's seeing a relationship here between his number bonds to 10 and these bonds, these pairs that make 100.

Hmm.

I wonder if there is always that link to number bonds to 10.

Should we take a look? So we know that 100 can be composed of 5 tens and 5 tens.

We've seen this before in this lesson.

So we can also say that 100 can be composed of 50 and 50 because 5 tens can be written as 50.

So we have 50 and 50 make 100.

I wonder if there is a number bond to 10 that we know that could help us with this.

So Andeep's relationship works here as well.

I know that five plus five is equal to 10.

So 5 tens plus 5 tens is equal to 10 tens, therefore 50 plus 50 is equal to 100.

Andeep has then written out some of his other equations using his number bonds to 10.

Have a look.

What do you notice about those two sets of equations? So on one side, we have our number bonds to 10.

And on the other side, we have two parts that make 100.

Do you notice? Hmm.

Well, Andeep has spotted that you can use your number facts to 10 to work out multiples of 10, which compose 100.

So if we know, for example, that 0 plus 10 is equal to 10, then zero plus 100 must equal 100.

If I pick another example, if I know that 4 plus 6 is equal to 10, then 40 plus 60 must equal 100.

Well spotted, Andeep.

That's a great thing to notice.

Time to check your understanding.

We know that 100 can be composed of 1 ten and 9 tens, therefore we know that 100 can be composed of 10 and 90.

I would like you to fill in the gaps in this sentence.

I know that 1 plus mm equals 10, so 1 ten plus mm tens equals mm tens, therefore 10 plus mm equals 100.

You can tell your partner those sentences or write them down if you don't have a partner.

Pause the video here and have a go.

How did you get on? Shall we say that sentence together? Are you ready? I know that 1 plus 9 is equal to 10.

So 1 ten plus 9 tens is equal to 10 tens, therefore 10 plus 90 is equal to 100.

Well done if you are managed to say all of those and fill in all of those gaps.

You can use these ideas of number facts and related number facts to solve problems. Let's take a look at these cars.

Izzy is playing with some toy cars and she measures to see how far each toy car has travelled.

So they've travelled the distance of those lines.

So we can see that car 1 on top has travelled 100 centimetres.

How far does car 2 need to travel to catch up with car 1? Hmm, well let's have a look.

Car 2 has so far travelled 70 centimetres and we know that car 1 has travelled 100 centimetres.

So we can use our stem sentence to help us.

I know that 7 plus 3 is equal to 10.

So 7 tens plus 3 tens is equal to 10 tens.

This must mean that 70 plus 30 is equal to 100.

So car 2 needs to travel an additional 30 centimetres in order to catch up with car 1.

You can use number facts to solve other problems. So earlier we looked at the idea that 100 could be composed of three different parts.

This time we have a bar model with one parts missing.

So we are told that 100 is equal to 30 and 20 and something.

So Andeep is setting as a challenge.

He's saying that three multiples of 10 make 100.

What is the missing number? Izzy thinks she can use her number bonds to help.

She knows that 3 plus 2 is equal to 5.

So we know that fact.

So therefore 30 plus 20 equals 50.

So those two parts added together must make 50.

That makes it a little bit easier I think.

Then she goes on to say that she knows that 5 plus 5 is equal to 10, so therefore 50 plus 50 is equal to 100.

She knows that the missing part must be 50.

50 is a multiple of 10.

So it fits with Andeep's challenge.

Well done, Izzy.

Great work.

Time to check your understanding.

We looked at a problem very similar to this earlier.

How much further does car 2 need to travel to catch up with car 1 this time? See if you can use your number bonds to think about it.

Use the sentence, I know that mm plus mm is equal to 10, so mm tens plus mm tens is equal to 10 tens.

Pause the video here and have a go.

How did you get 'em? So the missing number is 50.

I know that 5 plus 5 is equal to 10.

So 5 tens plus 5 tens is equal to 10 tens.

50 plus 50 is equal to 100.

Well done if you said that.

Time for your final practise of this lesson.

Question number one.

Andeep and Izzy have been running.

They each ran a multiple of 10 metres, and together they ran 100 metres.

Andeep is saying, "I ran mm metres." Izzy ran mm metres as well.

But remember together they ran 100 metres.

How many different ways can you find to combine two multiples of 10 to make 100 metres? Question two.

Andeep, Izzy, and Jacob all have some 10 pence coins.

Altogether they have 100 pence because they know that ten 10 pences is equal to 100 pence.

Your questions are, how much money does Jacob have if Andeep has 60 pence and Izzy has 10 pence? Andeep has 20 pence and Izzy has 30 pence? And Andeep has 70 pence and Izzy has 20 pence? Now, for the first two, you have some coins to help you remembering that ten 10 pence coins make 100 pence.

The third one's a bit trickier because you don't have that to help you.

Pause the video here.

Have a go at those two tasks and then come back when you're ready for some feedback.

How did you get up? Let's have a look at those first answers.

Now, there are lots of different options here as you can see on the screen.

For example, if Izzy ran 10 metres, Andeep would have to run 90 metres.

If Izzy ran 60 metres, Andeep would have to run 40 metres.

Did you manage to find all of those different ways? And did you organise your work to find all the ways? Remember what we said earlier? If one of the parts increases by 10, the other part decreased by 10.

So that might have been a really good way to find all of the answers.

Well done if you've got every single one of those answers.

And here are the answers for question two.

Let's have a look at a together.

Andeep had 60 p, Izzy had 10 p, and we were looking to find out how much Jacob had.

We know that they have 100 pence altogether.

If Andeep had 60 p and Izzy has 10 p, we can add those together to make 70 p.

We know that the three of them have 100 pence, so we know that 7 plus 3 is equal to 10, so therefore 70 plus 30 is equal to 100.

So Jacob had 30 pence.

For b, Jacob had 50 pence.

And for c, Jacob had 10 pence.

Well done if you worked out all of those answers.

We have come to the end of the lesson and I know you've worked incredibly hard about thinking of multiples of 10 that total 100.

Let's think about what we've learned today.

There are 10 tens in 100, and knowledge of bonds to 10 can be applied to multiples of 10.

So if we know that 4 plus 6 is equal to 10, then 4 tens plus 6 tens is equal to 10 tens or 40 plus 60 is equal to 100.

Thank you so much for learning with me today and I look forward to seeing you again.