Lesson video

Hello, and welcome to one of our multiplication/division lessons.

My name is Miss Thomas and I'm really excited to go through this lesson with you today.

I've had a fabulous day so far, because the sun has been shining.

So I've managed to spend lots of time outside getting some fresh air.

I hope you've had a lovely start to your day, too.

So let's get started.

In today's lesson agenda, first, we'll be exploring how to represent word problems using bar models.

Then we'll move on to our talk task where you can have a practise.

After that, we'll learn how to spot multiplication word problems using bar models.

Finally, we'll finish off with a quiz where you can test yourself on the learning.

For today's lesson, you're going to need a pencil, paper and ruler.

Pause the video now, if you need to get any equipment.

We have two star words.

The first is part.

My turn, part.

Part means one amount that makes up a whole.

The second word is whole.

My turn, whole.

Whole means complete including all of the parts.

Let's look them in our minds, because they're going to be important in this lesson.

Here, we have a word problem.

Before we can solve it, we need to understand what it's asking us to do.

Pause the video now and decide what maths is needed to be done in order to solve it.

Great job.

Let's explore together to see if you're right.

I'm going to read the word problem now.

See if you can track it with your finger.

Tim's cafe is so busy.

He needs to open a new room upstairs.

He has plenty of tables, but he doesn't have any more chairs.

There are four large tables with enough room for six people to sit around each one.

How many chairs should he get? Okay.

The question's asking me how many chairs he should get.

So I need to underline that, because that's my problem.

I'm also going to underline that he has four large tables and six people can sit around each one.

I'm going to represent this pictorially, using a bar model to help me solve it.

Okay.

So there are four equal parts, because that's the number of tables.

Drawing my four equal parts.

Each part has a value of six, because they're my chairs sitting around each one.

Okay.

Drawing my value of six for the chairs.

To find the value of the whole, that's my number of chairs around all four of those tables, I'm going to need to multiply six by four to give me my whole that's the missing value.

I know that six times four using my multiplication facts is equal to 24.

So he's going to need 24 chairs.

Here, we have a word problem.

It says, Peta has saved 24 pounds to go to the cinema with.

She buys one ticket to six pounds.

How much money does she have left? Meet Abzunafi and Efran.

They're trying to represent the word problem.

Abzunafi asks, do we start with the whole or the parts? I think, we start with the whole which is 24.

Efran agrees.

He says the whole is 24.

One part is six pounds.

And the other part is what she has left.

And that's what we're trying to find out.

Abzunafi agrees saying, there are two parts with different values.

The whole is 24, one part is six.

This is the correct bar model.

This is not a multiplication problem though, because it doesn't have equal parts.

Now it's your turn to represent a word problem.

If you're feeling confident, have a go.

If you need a little bit more time, we'll go through the answers together.

Read the word problem carefully and underline the key information, then complete your bar model.

Don't forget to completely say out loud sentence stem, once you've done your bar model.

This will help you decide if it's a multiplication problem.

Pause the video now.

Great job! Let's check together.

Here is the bar model that represents the problem.

You can compare it to yours.

Let's say the sentence stem together to see if you got it right.

The whole is 30.

There are three parts with different values.

We've got 18, six and the unknown value.

This is not multiplication.

All the parts are not equal.

So this is not a multiplication.

Give yourselves a tick, if you've got that or correct it, if you got it wrong.

Now it's your turn to have a practise.

Read the word problem and match it to the correct bar model.

Pause the video now.

Great job.

Let's have a look at the answers together.

Nelly has saved 18 pounds to spend at the shop.

She spends 18 pounds equally on three items. How much did each item cost? Here, we know that the whole is 18 and we must share it equally by three.

This should match with this bar model.

My equation is 18 divided by three is equal to six.

This is a division equation, but I represent it in the same way I would a multiplication, because they are the inverse operation.

Next, let's look at the problem below.

Sam wins two prizes on Thursday.

On Friday, he wins five times as many.

How many prizes does Sam win on Friday? This should match with this bar model.

I know my value of the part.

I know that my value of the part is two and I will need five of those parts to find my whole.

This is a multiplication, because my parts are split equally.

My equation is five multiplied by two is equal to 10.

Finally, let's look at the last one, but before we do, pause the video and explain what do you think this is a division or multiplication problem.

Remember the parts must be equal, if it's a division or multiplication.

Great job.

You've got it.

It's not a division or a multiplication, because the parts are not equal.

The whole is 10 and one of the parts is three.

The other part must be seven.

And we know that seven and three are not equal.

So our equation must be 10, take away three gives us our answer the missing part which is seven.

Congratulations! You are ready for your independent task.

Use the questions to match the word problem into the bar model.

Once you've done that, decide if it's a multiplication problem or not.

Remember the parts must be equal, if it is multiplication or the inverse division.

Pause the video now and have a go.

Here are the answers.

Which ones were multiplication equations? Was it number one, number two, number three? You've got it.

The first and the last number one and number three, because the parts were equal.

Now it's time to draw your own bar models.

Choose a problem to represent and decide if the problem needs multiplication or division to solve it.

Remind me what will the parts be if it does.

Excellent! That's right, equal.

Pause the video now and have a go.

Excellent effort on your bar models and well done for spotting those equal parts for multiplication and division problems. Here are the correct bar models.

Give yourselves a tick or correct them, if they were wrong.

Now, can you say out loud which ones are multiplication or division problems? That's right.

All of them.

And you knew that, because all of them were had equal parts.

If you'd like to, please ask your parents or carers to share your work on Twitter tagging @OakNational and hashtagging with the #LearnwithOak.

Great work today.

The time has come to complete your quiz to see just how much you've remembered.

I'm sure it's going to be a lot.

Excellent work.

Well done.