# Lesson video

In progress...

Hi, my name is Mrs. Behan, and I'm going to be your teacher for this lesson.

In this lesson, we are going to learn how to link multiplication to place value.

I've got a couple of games for us to play, and then a couple of activities for you to do.

Are going to beat me at these games? Let's play and find out.

Let's take a look at the agenda for this lesson.

Our ultimate goal in this lesson is to be able to see the relationships between the columns and the place value charts.

We will use our understanding of place value to multiply by 10, nice and easy.

We are going to play a game to begin with.

I'm going to show you some examples then to help you find the secrets of this lesson, we will then complete the practise activity together, and then you'll be ready to do an independent task.

I know you will be keen to find out how you got on.

So I will make sure that I go through the answers with you.

You will just need two things, something to write with.

So a pen or a pencil and something to write on.

If you haven't got those things handy, pause the video whilst you go and get them.

Try to work in a quiet place where you won't be disturbed.

The game we're going to play now is called beat the teacher, on your screen you will see a multiplication question.

You have to try and answer it before I do.

Do you think you're going to beat me? I think I'm going to get six out of six.

How many do you think you all going to get? Let's have a go and see.

Six multiplied by 10 is equal to what? I've got my answer.

Next question.

What is the product of six and 100.

So something is equal to six times 100.

Now remember timesing by 100 or by 10 and times by 10 again.

I've got my answer, next question.

Something is equal to 60 multiplied by 10.

Got it.

70 multiply by 10 is equal to what? I think I know this one.

Are you beating me? Next question.

Something is equal to seven times by 10, or seven multiplied by 10.

What is the product of seven and 10? That was a easy one, next question.

Our last question.

Something is equal to seven times 100, or seven multiplied by 100.

Can you work it out for our last question? Done, let's see how you got on.

So what was the product of six and 10? It was 60.

The products of six and 100, is 600.

The product of 60 and 10, is 600.

70 multiplied by 10 is equal to 700.

What's the missing number here? Seven multiplied by 10, is equal to 70.

And here our missing number is 700.

700 is equal to seven multiplied by 100.

How did you get on? I managed to get six.

I'm just going to remind you of some key facts that might help you.

We know that 10 is 10 times greater than one.

You can see here.

I have recombined all of my ones to make a 10, and I've had to make sure that my 10 goes in the 10s column and now don't need the ones.

Can you say 10 is 10 times greater than one.

You might want to judge it up a bit and say it in an animal voice.

Maybe a small animal, like a mouse.

10 is 10 times greater than one.

Here we can see how 10 10s can be recombined into a 100s block.

We know that 100 is 10 times greater than 10.

Perhaps you can say that in a lion's voice because it's a much bigger animal.

100 is 10 times greater than 10.

We can also see the calculation 10 multiplied by 10.

We also know that 100 is 100 times greater than one.

This is a big one.

Are you ready to use a really loud voice? 100 is 100 times greater than one.

Gosh, I'm sure I could hear you from all the way over here.

I took one block and multiplied it by 100 and it made 100 little ones.

And now it has the same value as the hundred block so I can use one of those, instead of using the 100 ones, the calculation we could use would be one multiplied by 100.

I wonder why my avatar over here is looking so excited about the word zero.

Maybe you know, could you have a go finishing this sentence for me? Zero is special because.

that's right, it is used as a place holder when we multiply by 10 or 100.

Fantastic, so you're going to see a number on your screen.

Tell me the number, Yes, it is number 23.

I'm going to pop it into a place value chart.

Here it is.

The three represents three ones and we know this because it is lined up in the one's colour.

The two represents two 10s, and we know this because it is lined up in the 10s colour.

The value of the two is 20 and the value of the three is just three.

Now I want to multiply 23 by 10.

So I want you to take a very close look at what happens next.

I'm going to multiply 23 by 10.

Just see if there's any movement and the place value chart.

What did you notice? You might have noticed, or you should have noticed that each digit has moved one place to the left.

Our three ones has now moved into our 10s column and that's because we have made the three, 10 times greater.

So our three now represents 30.

We had two in here that now represents 200, because we made our two 10s 10 times greater.

So our two now represents 200.

So 23 multiplied by 10 is equal to 230, but it's important that we use zero as our place holder.

Just to show that there are zero ones.

If that wasn't there, it would look like the number 23.

So we need to make sure that we have the zero there as a place holder to show this is 200, and that this is 30.

23 multiplied by 10 is equal to 230.

So we're going to work out the secret of this lesson by filling in the missing words.

I'm going to read it to you.

When multiplying by 10 or 100 we use zero as a blank blank.

When multiplying by 10, the ones move left into the blank column.

When multiplying by 10, the 10s move left into the blank column.

What do you think the missing words are? Let's go through it together.

Please can you read it with me? When multiplying by 10 or 100, we use zero as a place holder.

When multiplying by 10, the ones move left into the 10s column.

When multiplying by 10, the 10s move left into the 100s column.

Please have a go at drawing yourself a place value chart.

This is how you do it.

If you have some scissors handy, you could also cuts out some circles and write one, 10, and 100 on them to make some place value counters.

I'm going to draw them in my example, but you could always cut out the circles.

If you know it helps you to move counters with your fingers.

So here you will see how I've multiplied 23 by 10, and you can see how I am drawing place value counters.

In number 23 there are two 10s and three ones.

Now I'm going to multiply by 10.

The three ones have moved one place to the left, and now our three 10s.

We have made them 10 times greater.

The two 10s have now become two 100s.

So we can see in my place value chart, I have two 100s, three 10s, and zero ones.

So now I'm going to show you some practise questions.

And I want you to remember to use your place value chart, to show the movement of the digits.

That is our focus of this lesson, to see the movement of the digits and how they move one place to the left.

My avatar is sat in the corner reminding you of using that zero as a special place holder.

Draw out the place value charts and counters for these calculations.

Once you've done that compare them.

What do you notice? 13 multiplied by 10 and 31 multiply by 10.

16 multiplied by 10 and 61 multiplied by 10.

Pause the video and have a go at the questions.

So let's first have a look at 13 multiplied by 10 and 31 multiply by 10.

So in this calculation I did 13 multiply by 10, and I understood that the product was 130.

I had one 10 and three ones they each moved to place to the left.

So now I had one 100, and three 10s.

So I had to use it as a place holder in my product.

So let's look with this larger calculation.

31 multiplied by 10 is equal to 310.

So I can see that I had three 10s, and one one, and each has moved over one place to the left.

They've been made 10 times greater.

So my one has now been made 10 times greater, and it's 10.

30 has been made 10 times greater.

And then that value is now 300.

So 31 multiplied by 10 is equal to 310.

Is it the same here with 16 multiply by 10, and 61 multiplied by 10.

Let's take a look.

16 multiplied by 10 is equal to 160.

We can see on this example that both have moved one place to the left again.

And here with 61 multiply by 10, that gives us 610 because our one has been made 10 times greater and now has a value of 10.

And our six 10s have been made 10 times greater and now have a value of 600.

So we can see that even when we multiply large numbers by 10, it is still the same.

Each digit moves one place to the left.

You know how to use a place value chart if you need it, have a go at answering these multiplication questions.

Then we will look at the answers together.

In this question it says, Penelope said that 32 multiply by 10 is 320, Luke said that 320 is 10 times greater than 32.

Who is correct? And how do you know? Pause the video to complete your task.

Once you've finished come back to me.

Okay then let's see how you got on, here are the answers.

17 multiplied by one is equal to 17.

17 multiplied by 10 equals 170.

And you can see our place holder has been used there to show it's not 17.

It is in fact 170.

The values have changed.

17 multiplied by 10 is equal to 170.

24 multiplied by one is equal to 24.

24 Multiplied by 10 is equal to 240.

24 multiplied by 10 is equal to 240.

I'm sure you could use the other questions to help you work out the missing numbers there.

520 is the product of 52 and 10.

520 is equal to 52 multiplied by 10.

520 is equal to 52 multiplied by 10.

let's look at this question together.

Penelope said that 32 multiplied by 10 is 320.

Luke said that 320 is 10 times greater than 32.

So who is correct, and how do you know? Well in fact, both children are correct, and we can see if we use our place value chart.

So you can see here, I've put in three 10s and two ones to represent number 32.

And if we multiply that by 10, we can see each value moves one place to the left and we can see we get 320.

So 32 multiplied by 10 is 320.

That's what Penelope said.

We also know 320 is 10 times greater than 32.

So Luke is also correct.

We're now coming to the end of our lesson.