Lesson video

Hello, my name is Mrs. Hopper, and I'm really looking forward to working with you in this lesson.

The lesson comes from a unit, "Introduction to Division Structures." So we're going to be looking at how we can divide numbers up.

Are you ready to make a start? If you are, let's get going.

In this lesson, we're going to use a division story to write a division expression.

We've got two key words in our lesson today.

They are division and expression.

I'll take my turn and then it'll be your turn.

Are you ready? My turn, division, your turn.

My turn, expression, your turn.

Well done.

I wonder if you know what those words mean.

We're going to be exploring them in our lesson today so look out for them as we use them to support our learning today.

There are two parts to our lesson.

In the first part, we're going to be asking the question, what is division? And hopefully, answering it as well.

And in the second part, we're going to be writing a division expression.

So let's make a start on part one.

And we've got Aisha and Jun helping us with our learning today.

Jun's mum owns a bakery, lucky Jun.

He says, "We sometimes help her with cakes and cookies." Aisha says, "We have to wash our hands really well before we help out." Really good thinking, Aisha.

It's really good to wash your hands before you handle any food even your lunch or your break time snack.

Jun says, "Mom sells all sorts of things.

I love her chocolate cakes most." Oh, there they are, they do look good, Jun.

Let's look out for those as we go through our lesson as well.

Jun and Aisha put some cookies into bags.

"There are six cookies.

Two cookies going to each bag." There they go, can you see two cookies going into each bag? Aisha says, "We can say that six has been divided into groups of two." Six is divided into groups of two.

Six is the whole number of cookies that we had and two is the number of cookies in each bag, the number in each group.

Divided means splitting into equal parts or groups.

And we've split the cookies into equal parts of two.

They've got some more cookies to put into bags here.

"There are 10 cookies," says Jun, "and two cookies go into each bag." There they go, two cookies going into each bag.

Aisha says, "We can say that 10 has been divided into groups of two." 10 is divided into groups of two.

10 is the whole number of cookies and two is the number of cookies in each bag, the number in each group.

And we've divided the cookies.

We've split them into equal groups and each group has two cookies in it.

This time they're going to put some cakes on plates.

Jun says, "There are 10 cakes and five cakes go onto each plate." And there they are, five cakes on each plate.

Aisha says, "We can say that 10 has been divided into groups of five." Can you see that? The 10 cakes have been divided into groups of five, five on each plate.

10 is divided into groups of five.

What do those numbers represent? Can you remember? That's right, 10 is the whole number of cakes that we started with.

And five is the number of cakes on each plate, the number in each group.

They've got some more cakes to put onto plates here.

A few more this time, I think.

Jun says, "There are 15 cakes and five cakes go onto each plate." There they go.

Five cakes on each plate.

All the 15 cakes have gone onto plates.

Aisha says, "We can say that 15 has been divided into groups of five." Can you remember what the numbers represent again? That's right, 15 is the whole number of cakes, the number we started with.

And the five represents the number of cakes on each plate, the size of each group.

15 has been divided into groups of five.

Time to check your understanding now.

Jun and Aisha put some cookies into bags.

"There are eight cookies.

Two cookies go into each bag." And there they go.

Two cookies in each bag.

Aisha says, "What are the missing numbers?" Hmm is divided into groups of hmm.

Pause the video, fill in the missing numbers.

And when you are ready for the answer and some feedback, press play.

How did you get on? That's right, eight cookies divided into groups of two.

Eight is the whole number of cookies that we started with.

And two is the number of cookies in each bag, the number in each group.

We've divided the cookies into equal groups of two.

They've got some more cakes to put onto plates.

"Five cakes go onto each plate.

There are 20 cakes," says Jun.

You just put something slightly different there.

There you go, the cakes onto their plates, five on each plate.

Aisha says, "The whole number is the total number of cakes." But Jun said it second this time, didn't he? He talked about the number in each group first.

But the whole is the total number of cakes.

And we need to start with the whole when we're thinking about division.

20 is divided into groups of five.

20 is our whole number of cakes.

And five is the number of cakes on each plate, the number in each group.

And we've made equal groups of five out of our 20 cakes.

Time to check your understanding.

There's some more cookies to put into bags.

"Two cookies go into each bag," says Jun.

"And there are four cookies." Aisha says, "What are the missing numbers?" In our stem sentence, hmm is divided into groups of hmm.

And there go the cookies into their bags.

Can you complete the stem sentence? Pause the video, have a go.

And when you're ready for the answer and some feedback, press play.

How did you get on? Did you spot what Jun did? He gave us how many were in each group first, didn't he? So we need to start with the whole Aisha's reminding us.

Four is divided into groups of two.

We had four cookies as our whole and we were dividing them into groups of two, two cookies in each bag.

So Jun gave us the number of cookies in each bag first, didn't he? But we have to remember that four was the whole.

So four is divided into groups of two.

Well done if you spotted that.

Time for you to do some practise now.

For question one, you're going to help Jun and Aisha put cookies into bags.

So for the first set of cookies, Jun says, "There are 12 cookies.

Two cookies go into each bag." For the next set of cookies, Aisha says, "Two cookies go into each bag.

There are 16 cookies." Can you fill in the stem sentences? And you might want to use the pictures to help you think about the groups.

And for question two, you are going to help them to put the cakes onto plates.

For the first one, Jun says, "There are 25 cakes.

Five cakes go on to each plate." And for the second one, Aisha says, "Five cakes go onto each plate.

There are 30 cakes." Again, you could use the cakes to help you.

Can you complete the stem sentences? Pause the video, have a go.

And when you're ready for the answers and some feedback, press play.

How did you get on? So here are the answers.

So remember Jun said 12 is the whole and the cookies were going into bags of two.

So 12 is divided into groups of two.

And you can see that we've put a ring around each pair of cookies.

Didn't have any bags to spare this time.

And for Aisha's problem, she wanted to remind you that 16 was the whole, she talked about the groups of two first but 16 cookies are divided into groups of two.

16 is our whole.

So we start with our whole when we're thinking about dividing.

And for question two, we were thinking about cakes in groups of five.

So for the first one, Jun says 25 was the whole.

25 is divided into groups of five.

And you can see that we've drawn around the groups of five cakes there.

And for the second set, Aisha gave you the number of groups first, didn't she? But she's reminding you that 30 is the whole.

So our sentence says 30 is divided into groups of five.

I hope you were successful.

And time to move on into the second part of our lesson.

This time we're going to be writing a division expression.

Jun thinks about division.

I think we've all been thinking quite a lot about division, haven't we? He says, "I wish there was an easier way of saying 'is divided into groups of.

'" Hmm, can you think of anything that could help him? Aisha says, "There is.

We can use a division symbol instead." Oh, do you know what the division symbol looks like? You might have seen it before.

There it is.

That's what it looks like.

It's a line with a dot over the top and a dot underneath it.

So let's see how we can use it.

We've got 10 cookies and they're divided into groups of two.

So we can say 10 is divided into groups of two.

But Aisha knows that the division symbol can represent that is divided into groups of.

So we can write 10 divided by two and use the division symbol.

It still means 10 divided into groups of two.

10 is our whole and it's divided into groups of two.

So there are two in each group.

Jun says, "How would you use the division symbol in this story?" "There are 14 cookies.

Two cookies go into each bag." Hmm, can you think how we could use the division symbol? So there are the 14 cookies and they've gone two into each bag.

14 is divided into groups of two.

Can you think how we might be able to use the symbol to help us? Aisha says, "We could use the division symbol in an expression." So an expression is when we use numbers and symbols to represent the mathematics.

We've represented it in numbers and words.

14 is divided into groups of two.

And now we can use a symbol.

14 is divided into groups of two.

The division sign means is divided into groups of, so our expression means the same as our sentence.

Time to check your understanding.

Jun and Aisha put some cakes onto plates.

There are 40 cakes.

We put five cakes onto each plate.

That's a lot of cakes, isn't it? There they all are on their plates.

Aisha says, "How can you write this division as an expression?" Can you use the stem sentence to help you and then turn it into a division expression? Pause the video, have a go.

And when you're ready for the answer and some feedback, press play.

How did you get on? So did you spot that we had 40 and we had divided it into groups of five.

So 40 is divided into groups of five.

And we know that the division symbol means, is divided into groups of, so we can put our numbers in.

40 was our whole number of cakes and five was the number in each group.

40 is divided into groups of five.

Our division symbol means is divided into groups of.

Well done if you got that right.

Being able to write this as an expression is going to be really useful as we go on learning more about division.

Jun and Aisha put cakes into boxes.

Oh, Jun, I think they're your favourite chocolate cakes.

He says, "There are 20 cakes we put 10 cakes into each box." There they go, 10 cakes going into each box.

And Aisha says, we can say that 20 has been divided into groups of 10.

And we can write that as a sentence with our numbers.

She says, "We can also write this as a division expression using our division symbol." Can you think what that's going to look like? That's right.

We know that the division symbol means divided into groups of, so our expression 20 with our division symbol and 10 means the same.

20 divided into groups of 10.

And you might hear people reading it 20 divided by 10.

Here are some more, even more chocolate cakes.

Jun says, "There are 30 cakes and we put 10 cakes into each box." And now we can see 10 cakes going into each box.

Aisha says, "We can say that 30 has been divided into groups of 10," and we can write that out using words.

But do remember Jun wanted to know if we could replace the words with a symbol and Aisha said yes we could.

So how could we write that as a division expression? That's right.

We know that the division symbol means divided into groups of, so we can replace all those words with that division symbol.

And it means the same.

30 was our whole group of cakes and we've divided it into groups of 10.

The 10 represents the size of the group, 30 divided into groups of 10.

Time to check your understanding.

Which division expression matches the story? There's lots more cakes here as well, aren't there? "We put 10 cakes into each box," says Jun.

There are 40 cakes.

Hmm, can you spot what he's done there? Can you find out whether it's A, B, or C, which is the expression to match our story.

Pause the video, have a go.

When you're ready for the answer and some feedback, press play.

How did you get on? Oh, well it wasn't B was it? This says 10 divided into groups of 40, which isn't our story.

Jun did talk about the groups first.

He put 10 cakes into each box first, and there were 40 cakes.

We had to remember that 40 was the whole and should start our division expression.

So B is not correct.

What about C? Well, no, that's incorrect as well.

It's a subtraction, 40 subtract 10.

So we might have taken one group of 10 and put them in a box, but we haven't divided all the cakes into equal groups of 10, have we? So A must be correct.

This says 40 divided into groups of 10.

We know that the symbol means divided into groups of, 40 represents the whole all the cakes that we started with.

And 10 is the number that we put into each box, the size of our group.

Well done if you've got that right.

Jun puts some cakes onto plates and he uses a division expression to explain what he's done.

Oh, he's starting with the expression and there's his expression, 35 divided by five.

And we know that the division symbol means divided into groups of.

Aisha says, "How should you write this as a division story?" What might our story be? She says, "Well, let's start with the whole in the story." So the whole is the number we start our division with, so 35.

So there are hmm cakes, there are 35 cakes.

How many cakes have been put onto each plate? Can we see that in the division expression? Well, that's right.

The division symbol means divided into groups of, and we've got a five there.

So five cakes are put onto each plate.

So 35 divided into groups of five.

The expression represents the fact that there are 35 cakes and five cakes are put onto each plate.

They represent the same thing.

Time to check your understanding.

Jun puts some cakes into boxes and uses a division expression to explain what he's done.

And there's his division expression.

And Aisha says, "How should you write this as a division story?" So there are our stem sentences.

Can you fill in the gaps in the stem sentences so that we can represent the story that Jun has explained with his expression? So can you fill in the gaps in the stem sentences to complete the division story that matches Jun's expression? Pause the video, have a go.

And when you're ready for the answer and some feedback, press play.

How did you get on? So in Jun's expression, we had 60 as our first number.

So 60 represents our whole.

There are 60 cakes and his division expression says divided into groups of 10.

So we know that the group size must be 10.

So there are 10 cakes into each box.

So our sentences say there are 60 cakes, 10 cakes are put into each box.

So that's the story that represents Jun's expression.

Well done if you've got that right.

And it's time for you to do some practise.

You're going to, for question one, write each story as a division expression.

We've given you the story and we've given you a picture there to help you.

And you're going to write the expression, fill in the gaps around the division symbol.

And for question two, we've given you the division expression and you are going to complete the division story, fill in the gaps using the numbers in the expression.

So pause the video, have a go, and when you're ready for the answer and some feedback, press play.

How did you get on? Here are the answers to question one.

So for A, there are 50 cakes and 10 cakes are put into each box.

So our whole is 50 and we are making equal groups of 10.

So it's 50 divided into groups of 10.

And that's how our expression looks using the division symbol.

For B, there are 18 cookies and two cookies are put into each bag.

So we've got 18 divided into groups of two.

18 divided by two.

And for C, five cakes are put onto each plate and there are 45 cakes.

Ooh, did you spot something? That's right, 45 is the whole, and 45 is what we are going to start our division expression with.

45 divided into groups of five, 45 divided by five.

In question two we were doing it the other way round.

You had the expression and you were going to fill in the gaps in our division stories.

So we had 20 divided into groups of two.

So 20 represents our whole.

There are 20 cookies and two represents the number of cookies in each group or in each bag.

So there are 20 cookies, two cookies are put into each bag.

In B, we had 45 divided into groups of five.

We know that the symbol means divided into groups of, so there are 45 cakes, that's our whole, and the five represents five cakes onto each plate.

So there are 45 cakes and five cakes are put onto each plate.

In C, we've got 70 divided into groups of 10, but our sentence said, hmm cakes are put into each box.

Ah, so we've got to remember 70 is our whole, there are 70 cakes is where we're going to start.

So the 10 represents the number of cakes in each box.

So our sentences are 10 cakes are put into each box.

There are 70 cakes.

Well done if you've got that right, especially if you spotted where we change the order of the whole and the size of the groups.

And we've come to the end of our lesson.

We've been explaining the relationship between division expressions and division stories.

We know that dividing into equal groups can be recorded as a division expression.

Eight divided into groups of two can be recorded with the division sign there, eight divided into groups of two.

Our division symbol means divided into groups of, and the whole can be divided by the number of objects in each group.

So we can read that as eight divided by two as well.

And you might well have heard that, but worth remembering that the division symbol means divided into groups of when we're thinking about putting cookies into bags and cakes into boxes.

Thank you for all your hard work today and I hope I get to work with you in another lesson soon, bye-bye.