Lesson video

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

The lesson comes from our 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.

So in this lesson we're going to be using skip counting to solve division problems relating to measure.

So let's get going.

Are you ready to do some good counting to help us today? Excellent.

We've got one keyword in our lesson today and that's division.

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

So my turn, division, your turn.

Excellent.

I hope that's a word you've been thinking about a little bit recently.

Anyway, we're going to learn more about it today in our lesson.

So look out for it as we go through.

There are two parts to our lesson today.

In the first part, we're going to be skip counting using number rods and in the second part, we're going to be solving measurement problems using skip counting.

So are you ready? Let's make a start.

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

Aisha and Jun are using number rods.

You might have some of these in your classroom.

If not, we'll teach you all about them as we go through this lesson.

The number rods are all certain lengths.

Sometimes we give them a number and sometimes we don't.

We're going to give them numbers in this lesson to help us.

We're going to use the number rods to help us to solve division problems. So in our lesson, we're going to say that our red rod represents two and the yellow rod represents five and the orange rod represents 10.

So we've got the red rod representing two, the yellow rod representing five and the orange rod representing 10.

Aisha and Jun use the number rods to calculate 10 divided into groups of two.

Aisha says we'll start with the orange rod because 10 is the whole and today, our orange rod is representing 10.

And Jun says, I'm going to use the red rods to find the number of groups of two equal to 10.

So there, he's placing the red rods along the orange rod.

How many has he placed? Well, Aisha says, five red number rods are equal to one orange number rod.

10 divided into groups of two is equal to five.

And we can record that as an equation using our division symbol 10 divided into groups of two is equal to five.

And we know that the division symbol can stand for divided into groups of.

This time, they're going to use number rods to calculate 10 divided by five.

Aisha says, we'll start with an orange rod because 10 is our whole and June says, I'm going to use yellow rods to find the number of groups of five equal to 10 'cause our yellow rod represents five.

And there are the yellow rods equal to one orange rod.

Two yellow number rods are equal to one orange number rod.

And let's think about the numbers we've given them.

10 divided into groups of five is equal to two and we can record that as an equation.

10 is our whole divided into groups of five is equal to two groups.

Aisha and Jen use the number rods to calculate 20 divided by five, 20 divided into groups of five.

Aisha says, we'll need two orange rods.

10 plus 10 is equal to 20.

So now we've represented our 20.

And Jun says, I'm going to use the yellow rod to find the number of groups of five equal to 20.

Can you think what it'll be? How many groups of five were equal to 10? Can you work it out? Ah, we've got two lots of 10 is equal to 20.

So we've got four lots of five.

Four yellow rods are equal to two orange rods and we can record that as 20 divided into groups of five is equal to four.

20 is our whole, our group was five and we have four of those groups to make our whole.

Aisha and Jun used number rods to calculate 14 divided by two, 14 divided into groups of two.

Aisha says, we'll start with an orange rod 'cause 14 is the whole but that's only 10, isn't it? Ah, Jun says we need to use a pink rod too.

Pink rod is equal to four and 10 plus four is equal to 14.

So now we've got a whole of 14 represented by our orange and our pink rod.

And we are working out how many groups of two those with the red number rods.

So let's see.

How many did you count? There are seven red number rods that are equal to one orange and one pink number rod.

And remember they were representing our whole of 14.

14 divided into groups of two is equal to seven and we can represent that with our equation.

14 divided into groups of two is equal to seven and our division symbol means divided into groups of.

Time to check your understanding.

Can you use number rods to calculate eight divided into groups of two? And can you complete the equation? A brown rod represents eight.

And do you remember which rod represented two? That's right.

Use the red rods to count in twos.

There they are.

Pause the video and see if you can complete the equation.

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

How did you get on? It was four, wasn't it? Eight divided into groups of two is equal to four.

Eight is our whole.

We were dividing into groups of two and there were four groups of two.

Time to check again.

You're going to use number rods to calculate 12 divided by two.

Can you remember which rods you're going to use? Start with an orange number rod and then we'll add a red one as well because that's equal to two.

10 plus two is equal to 12.

So there's our whole of 12 and then we're going to use the red number rods to find out how many groups of two, 12 divided into groups of two.

So can you complete the sentence and the equation to show what 12 divided into groups of two will be? Pause the video, have a go and when you're ready for some feedback, press play.

What could you see there in the image? Well, we could see 12 divided into groups of two is equal to six.

There are six groups of two making up our whole of 12 and we can record that as 12 with the division symbol meaning divided into groups of 12 divided by two is equal to six.

12 represents our whole, two represents the size of each group and six represents the number of groups.

12 divided into groups of two is equal to six.

Aisha wants to divide 15 into groups of two.

She says, I'll use an orange rod and a yellow rod to represent 15.

10 plus five is equal to 15 and she's going to use her red number rods, which are worth two to see how many fit along her whole of 15.

Can you see what's going to happen? Oh.

Jun says, 15 does not divide into an exact number of groups of two.

There are seven groups of two and there is one not in a group of two.

To divide exactly into groups of two, a number has to be even.

We know that even numbers can be made from groups of two.

15 is an odd number so it can't be made from groups of two.

We can't find a whole number of two rods that will equal 15.

Time for you to do some practise mow.

You are going to use number rods to complete the division equations.

So in A, we've got six divided by two, six divided into groups of two.

In B, we've got 16 divided into groups of two.

And in C, we've got 15 divided into groups of five.

And we've given you the number rods that represent the whole in each equation.

And remember the red number rod represented two and the yellow number rod represents five.

And the dark green rod represents six.

In question two, again, you're going to use the number rods to complete the division equations.

20 divided into groups of two, 20 divided into groups of 10 and 25 divided into groups of five.

Use the correct number of orange rods to make 20.

Pause the video, have a go at the divisions and when you're ready for the answers and some feedback, press play.

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

So six divided into groups of two.

We were using the red number rod and three red rods were equal to one green rod.

Six divided into groups of two is equal to three.

In B, Aisha says 10 plus six is equal to 16 and orange rod and a dark green rod are equal to 16.

So that was our whole, but we were dividing 16 into groups of two.

So how many of the red number rods are equal to an orange and a green? And that was eight.

16 divided into groups of two is equal to eight.

16 was our whole, two is the size of our group and eight of those groups of two were equal to 16.

And in C, we had 15 divided into groups of five.

So an orange and a yellow rod were equal to our whole of 15.

And then our yellow rod was our part as well.

So how many of those yellow rods could fit along? And the answer was three.

15 divided into groups of five is equal to three.

And for question two, you were using the orange rods to make 20, two groups of 10 to equal 20.

20 divided by two is equal to 10.

We could fit 10 of the red number rods along the two orange rods.

And in B, we had 20 divided by 10.

So that's interesting, isn't it? We used two orange rods to make the 20 and along that, we could fit two groups of 10.

So 20 divided into groups of 10 is equal to two.

And in C, we have 25 divided into groups of five.

So we needed two orange rods and one yellow rod to represent the 25.

And then we were finding out how many groups of five represented by the yellow rods.

And Aisha spotted that two yellow rods are equal to each orange rod.

So we had two lots of two and one more.

So we had five lots of five equaling 25.

25 divided into groups of five was equal to five.

How did you get on with those? I hope you enjoyed exploring those divisions with the number rods.

And onto part two of our lesson.

This time we're going to be solving measurement problems using skip counting.

Aisha and Jun use number rods alongside a ruler.

And can you see we've got a ruler here.

It won't be showing accurate centimetres on your screen I'm sure, but I'm sure you might be able to see a 30 centimetre ruler around by you somewhere.

And Aisha says, each number rod is an exact number of centimetres long.

Jun says, the red rod is exactly two centimetres long and you can see it there on our ruler.

The yellow rod is exactly five centimetres long.

The orange rod is exactly 10 centimetres long.

Aisha and Jun have a piece of card four centimetres long.

How many two centimetre long pieces can they cut it into? So their whole piece of card is four centimetres long and they want to know how many two centimetre pieces they can cut it into.

Aisha says, we're going to work out how many two centimetre rods are equal to four centimetres.

So one length is two centimetres, two lengths are four centimetres.

Our two rods have come up to four centimetres on our ruler.

Four centimetres divided into groups of two centimetres is equal to two.

Jun says, we can cut a four centimetre piece of card into two two centimetre pieces.

This time they have a piece of card 18 centimetres long.

How many two centimetre long pieces can they cut it into? Aisha says, we're going to work out how many two centimetre rods are equal to 18 centimetres.

Let's have a look.

One, two, three, four, five, six, seven, eight, nine.

18 centimetres divided into groups of two centimetres is equal to nine.

Our whole is 18 centimetres, our parts are two centimetres long and we can make nine of those parts from our 18 centimetres.

We can cut an 18 centimetre piece of card into nine two centimetre pieces.

This time, Aisha and Jun have a piece of card five centimetres long.

How many five centimetre long pieces can they cut it into? Hmm.

Aisha says, we're going to work out how many five centimetre rods are equal to five centimetres.

Can you predict this, do you think? Oh, one length is five centimetres.

Five centimetres divided into a group of five centimetres is equal to one.

We can get one piece of five centimetre card.

Jun says, we don't need to cut it.

There is only one five centimetre piece.

Time to check your understanding.

Aisha and Jun have a piece of card 30 centimetres long.

How many five centimetre long pieces can they cut it into? Aisha says, work out how many five centimetre rods are equal to 30 centimetres.

So remember that the five centimetre rods are the yellow ones.

So pause the video, have a go.

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

How did you get on? How many five centimetre pieces could they cut their card into? Let's have a look.

One, two, three, four, five, six.

30 centimetres divided into groups of five centimetre is equal to six.

We can cut a 30 centimetre piece of card into six five centimetre pieces.

Aisha and Jun have a piece of card 35 centimetres long.

How many five centimetre long pieces can they cut it into? Can you use the last answer to help you, do you think? Oh, Aisha says, I'm using a metre stick to work out how many five centimetre rods are equal to 35 centimetres.

Her ruler didn't go any further than 30 centimetres, did it? Let's count with them.

One, two, three, four, five, six, seven.

We could count in five.

Should we try that? Let's try again.

Are you ready? Five, 10, 15, 20, 25 30, 35.

35 centimetres divided into lengths of five centimetres gives us seven pieces.

We can cut a 35 centimetre piece of card into seven five centimetre pieces and we counted how many rods and then we also counted in fives to check, didn't we? Time to check your understanding again.

Aisha and Jun have a piece of card 30 centimetres long.

How many 10 centimetre long pieces can they cut it into? If you've got some number rods, you might be able to use a yellow number rod against your ruler to help you.

Otherwise, perhaps you could use skip counting to help you.

Remember, 10 centimetre long pieces and we want to know how many there are in 30 centimetres.

Pause the video, have a go.

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

How did you get on? Aisha and Jun used the number rods to help them.

So one length is 10 centimetres, two lengths are 20 centimetres and three lengths are 30 centimetres.

So 30 centimetres divided into groups of 10 centimetres is equal to three.

We can cut a 30 centimetre piece of card into three 10 centimetre pieces.

30 divided into groups of 10 is equal to three.

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

In question one, you're going to use number rods and a 30 centimetre ruler to work out the answers.

So A says, how many two centimetre lengths are equal to 22 centimetres.

B is, how many two centimetre lengths are equal to 24 centimetres.

And C, how many 10 centimetre lengths are equal to 10 centimetres.

And can you record those as division equations? And then in question two, you're going to use the number rods and a metre stick to work out the answers.

How many five centimetre lengths are equal to 40 centimetres, that's A.

In B, how many 10 centimetre lengths are equal to 40 centimetres.

And in C, how many five centimetre lengths are equal to 50 centimetres? And again, can you record those as division equations and you can see the blanks there.

Pause the video, have a go at the two questions and when you're ready for some feedback, press play.

How did you get on? So A, wanted to know how many two centimetre lengths are equal to 22 centimetres.

So our equation would be 22 centimetres divided into groups of two centimetres and that's equal to 11.

Let's have a look.

Two, four, six, eight, 10, 12, 14, 16, 18, 20, 22.

That was 11 lots of two centimetres.

11 two centimetre lengths are equal to 22 centimetres.

So 22 divided into groups of two is equal to 11.

In B, how many two centimetre lengths are equal to 24 centimetres? Well, that's another one, isn't it? An extra one would give us 12 lots of two centimetres.

So 24 divided into groups of two is equal to 12.

And in C, how many 10 centimetre lengths are equal to 10 centimetres? Well, if we imagine the 10 centimetre rod on our ruler, we'd see that there was one.

10 centimetres divided into a group of 10 centimetres gives us one group, doesn't it? So in question two, our numbers were slightly bigger, so we might have needed a metre stick rather than a 30 centimetre ruler.

So A said, how many five centimetre lengths are equal to 40 centimetres? Five, 10, 15, 20, 25, 30, 35, 40.

That was eight five centimetre lengths.

So 40 centimetres divided into groups of five centimetres is equal to eight.

Eight five centimetre lengths are equal to 40 centimetres, says June.

In B, how many 10 centimetre lengths are equal to 40 centimetres? Or can you imagine, two of those fives going together to make a 10? 'Cause we know that five plus five is equal to 10, so that would be four 10 centimetre lengths.

40 centimetres divided by 10 centimetres is equal to four.

40 centimetres divided into groups of 10 centimetres would be equal to four groups.

And in C, how many five centimetre lengths are equal to 50 centimetres? Well, we knew that eight was equal to 40, so we'd need two more fives, 45, 50.

So another two five centimetre lengths, so that would give us 10.

50 centimetres divided into groups of five centimetres is equal to 10.

Well done if you worked all of those out and well done if you did some skip counting with it too.

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

We've been using our knowledge of skip counting and division to solve problems relating to measure.

Skip counting can be used to calculate the number of equal groups in a division story.

You can use skip counting to work out the number of shorter lengths that are equal to one longer length.

For example, 50 centimetres divided into groups of 10 centimetre lengths is equal to five.

50 divided into groups of 10 is equal to five, and we can count up in tens, 10, 20, 30, 40, 50 five groups of 10.

So for this problem, there are five groups of 10 centimetre lengths in 50 centimetres.

I hope you've enjoyed exploring measures and skip counting and number rods in our lesson today and I look forward to working with you again soon.

Bye-bye.