Lesson video

Hello, everyone, my name is Miss Sabzvari.

And I'm really excited that you decided to join me today for our maths lesson.

The unit we're studying is multiplication and division.

In the previous lesson, we look at solving division problems while grouping.

In this lesson, we will focus on finding related multiplication and division facts.

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

Let's have a look at today's lesson agenda.

First, we'll begin by exploring the relationship between multiplication and division.

Then we'll move on to a talk task.

Next, we'll describe partly hidden arrays.

And finally, you will complete your independent task.

Before we begin today's lesson, you will need the following items. You will need something to write with and something to write on, and you will need some counters or cubes.

Alternatively, you can ask your parent or carer to cut out some small pieces of paper that you can use instead.

So please pause the video now and get the items that you need.

Exploring the relationship between multiplication and division.

Let's have a look at what division and what multiplication actually means.

So in division, follow with me, the whole is divided into parts, whereas in multiplication, parts are multiplied together to find the whole.

So pause the video now and tell your screen what is the difference between multiplication and division? Excellent work.

So in division we know the whole and we're dividing it into parts, whereas in multiplication, we have our parts and we are multiplying them together to find the whole.

Great work.

So, have a I look at the array on your screen.

Pause the video and tell your screen what is the value of the parts? And what is the value of the whole? And how many parts are there? Great work.

So we know that there are four parts, one, two, three, four.

And each part has the value of two.

Okay, there are two counters in each part, and the whole is eight.

So, two, four, six, eight.

Okay, so I'm going to describe how many parts there are.

Then what the value of each part is.

And finally, the whole, how many I have altogether.

Great.

What equations describe this array? I'd like you to pause the video and write down all of the equations that you can possibly think of to describe the array on our screen.

Do that now.

Excellent work.

So I could say that four most multiplied by two, so four, one, two, three, three, four groups of two is equal to eight.

I could say that two groups of four is equal to eight.

Alternatively, I could write two division equations, and I could say that eight divided into two groups is equal to four, and eight divided into four equal groups, is equal to two.

So for this array, we could write two multiplication and two division equations.

So, let's play a game.

What I'm going to start doing is I'm going to describe an array.

And what you're going to do is you're going to create that array using your counters.

And then you're going to draw the array on your piece of paper.

So let's have a little practise together and you see what I mean.

There are two parts.

Each part has the value of six.

The whole is 12.

Draw the array or create theory using your counters.

Then you're going to write to two multiplication and the two division equations for the array.

Okay, so I know that there are two parts, and each part has the value of six.

So first, I'm going to place my counters to represent my two parts.

And I know the value of each part is six.

So one, two, three, four, five, six.

And I'm going to do the same for my second part, three, four, five, six, and the whole is 12.

Two, four, six, eight, 10, 12.

Alternatively, if I didn't want to use counters and I just wanted to draw my array, I know that there are two parts.

So one, two, and I know the value of each part is six, so one, two, three, four, five, six.

Two, three, four, five, six.

And I know that the whole is 12.

Two multiply by six is equal to 12.

Six multiplied by two is equal to 12.

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

And 12 divided by six is equal to two, and 12 divided by two groups is equal to six.

Follow with me, there are five parts.

Each part has a value of three.

The whole is 15.

Pause the video now to create your array.

Draw the array.

And finally, write down your multiplication and division equations to describe the array.

Great work.

So I know that there are five parts.

So one, two, three, four, five.

And I know that each part, the value is three.

So I'm going to create my first group of three, my second, my third, my fourth and my fifth group of three.

And then I'm going to check that the whole is 15.

Okay? Great.

So let's have a look at our equations.

I know that five groups of three is equal to 15.

So one group of three, two, three, four, five groups of three is equal to 15.

I know that three groups of five is equal to 15.

Good.

I know that 15 divided into five groups is going to equal to three.

And finally, I know that 15 divided into three equal groups is going to equal to five.

You guys have a big pat on the back, if you've got that correct.

Well done.

There are two parts.

Each part has a value of five.

The whole is 10.

Let's have a look at the answers together.

So I know that there were two parts, one, two, and I know that in each part, there are five.

So I'm going to make sure that in my array, I have five dots.

And I know that the value is equal to 10.

Good work.

And for our equations, we know that two groups of five, so two, multiplied by five is equal to 10.

We've got one group of five here, two groups of five.

I know that five groups of two is equals to 10.

Okay, so I've got one group of two, and all the way to the top.

I know that 10 divided into two equal groups is equal to five, so 10 divided by two.

So, I've got one group of five and another group of five.

And I know that 10 divided by five is equal to two.

So one, tow, three, four, five.

So one group, two, three, four, five.

I know two counters in each group.

Great work.

Okay, so let's swap.

This time, you are going to see the array and you are going to describe the array to me.

Okay, so you're going to pause the video, and you're going to describe the array to your screen.

Then you going to write the multiplication and division equations for the array that you have just described.

Okay? So there's a sentence frame here which you can use to help people.

So there are, parts.

Each part has the value of.

The whole is.

Okay, so pause the video now and describe the array.

Great work.

So you should have had that there are three parts.

So one, two, three.

Each part has the value of four.

The whole is 12.

Great work.

And let's have a look at your multiplication and division equation.

You could have had that three multiplied by four is equal to 12.

So one, two, three groups of four.

You could have four multiplied by three is equal to 12.

So one, two, three, four.

Four groups three.

Or you could have 12 divided into three equal groups, is equal to four.

So 12 divided by three, one, two, three, is equal to four.

And 12 divided by four is equal three.

So describing partly hidden arrays.

So let's have a look at the array on your screen.

What I would like to do is to pause the video and tell me how many counters are in my array altogether.

Do that now.

Great work.

So I know, I can see how many parts there are.

So one, two, three, four parts.

And I know the value of each part.

So I know that one, two, three, four, five.

I know that there are five counters in each group.

Okay, so I've got four groups of five.

So what I would like you to do now is to draw the array and to write down the multiplication and division equations to describe the array.

Do that math.

Excellent work, so we know that there are four groups of five, which equals 20.

And we know that multiplication is commutative, so I know that five multiplied by four is also equals 20.

Okay, so I've got one, two, three, four, five groups of four.

So I would be able to draw my array based on that information.

Then because I know the whole, I can write my division equations too.

I know that 20 divided by four is equal to five.

Okay, so 20 divided into four equal groups, two, three, four, is equal to five because I've five in each group.

And I know that 20 divided by five, one, two, three, four five, is equal to the four.

We've four in each group.

Now it's time to independent task.

So, what you're going to do is, you're going to create these arrays using your concrete manipulatives.

So using your cubes and counters.

Then for each array, what I would like you to do is to describe them with two multiplication equations, and two division equations.

And once you're finished, we will go through the answers together.

Lets have a look at the first array.

I know that there are one, two, three, four parts, and each part have got a value of three.

So I know that four multiplied by three is equal to 12.

I also know that multiplication is commutative.

So you've three, one, two, three, multiplied by four is equal to 12.

I've got my division equations.

I know 12 divided by four, or split or shared into four equal groups is equal to three, and 12 divided by three is equal to four.

Moving onto our next array, I have one, two, three, four, five groups of three.

So, five multiply by three is equal to 15.

I know that three groups of five, so three groups of five is equal to 15.

And I know that 15 shared into five equal groups is equal to three.

And I know that 15 divided by three is equal to five.

And looking at this array, I know that there are four groups, and each group has a value of five.

So I know that four multiplied by five is equal to 20.

I also know that five groups of four is equal to 20.

Therefore, 20 divided by four is equal to five, because I've have four groups, one, two, three, four, and in each group, the value is five.

And 20 divided by five is equal to four.

And finally, looking at our last array, I know that six, there are six groups, so one two, three, four, five, six.

And the value of each part or the value of each group is three.

So you've multiplied by three is equal to 18.

And three multiplied by six is equal to 18.

I also know that 18 divided into six equal groups is equal to three.

And I know that 18 divided by three is equal to six.

And if you'd like to, please ask your parents or carers to share your work on Twitter tagging @OakNational and #LearnwithOak.

And now it's time for you to complete your end of lesson quiz.

See you next.