Lesson video

Hello everyone.

I'm Mrs Crane and welcome to today's lesson.

In today's lesson, we're going to be solving word problems by using bar models.

How are you today? I hope you're well, and I hope you're ready for some maths.

Don't worry about getting any resources just yet.

I'll explain all of the equipment that we'll need in just a moment.

But, if you can, please can you turn off any notification on your phone, tablet or whatever device you're using to access the data now.

And then if you can, try and find somewhere nice and quiet in your home so that we're not going to be disturbed during today's lesson.

When you're ready let's begin.

Okay then, let's run through today's lesson agenda.

So, we're going to be looking at double, three times as many, and four times as many.

Then we're going to look at today's talk task, which is going to be a matching activity.

We're going to match some things together.

Then we're going to look at bar models and word problems. And then for your independent test today, you're going to be using the bar models to solve some equations.

So, before we get started, if you don't already, could you please get yourself a pencil and some paper and for today's lesson it'd be great if you can get yourself some counters.

They don't have to be multilength, it could just be that you've got some raisins in your cupboards, some dry pasta in your cupboard, or you might have some Lego that you could use as counters.

Pause the video now to go and get these things if you haven't got them already.

Okay, welcome back.

Let's get started then.

So, what do you notice is the same and what is different about these two bar models here? What is the same and what is different? Well, I can see that my main bar represents has been split into two here.

And I can see here that my main bar has also been split into two.

But I can see what's different here is that we've got another bar kind of clumped on the top of it.

So let's think here.

Could you use the words double or half to talk about these bar models? So I could say that this amount here is half of the whole amount here.

And I could say here, that this is almost like saying double this amount here.

Because you can see there that this is two parts here and there's that extra part that's on top of this part here.

Just like saying double one of the parts here.

You can still see that the whole represents here but you can see that this part, this new block that's been put on the top is the same as one of those halves here.

Now, could you use the words twice as many to talk about these bar models? Well I could say that in this half here, there's twice as many in total than in one part here.

But this bar model here, really lends itself well to saying that.

Because I could say there's twice as many here than here.

Now, what's the same and what is different about these two bar models here? Could I use the word three times as many? Notice how much our bar has been split into here.

And this is where it comes back to using some of our fractions knowledge.

So I can see here that my main bar has been split into one, two, three.

So each part of it here represents three, well represents a third of the bar.

So here, I can see that this represents one part and there are three parts of them.

So it represents a third.

Could I use the words three times as many? Well you'd have one, two, three, wouldn't you? So you could use that when we're looking at this bar model.

Could you use the words a third? Yes, you could.

You could say there's a third because that's one part of our whole here.

And here, we notice that that other bar has kind of been plunked on top of it again.

That really helps us when we come to thinking about we're looking at an extra part here which represents the same as one of our thirds here.

Now, how would you describe this bar model? Have a look.

Could you use the words four times as many when you think about this bar model here? Because my bar has been split into one, two, three, four.

Could you use the words a quarter? Well I know that here would be a half, and my half has been split into two again.

So I know each of these parts, they're equal parts, represents one quarter.

So yes, I could use a quarter to talk about this bar model here.

Now it's time for you talk task.

Which is going to be a matching activity.

You're going to look at some of the bar models that we've just been looking at and you're going to be matching them together.

So I'm just going to hide myself so you can see your talk task.

So what I'd like you to do for today's talk task is match the words, so these words here, with the most suitable bar models that are here for you.

Pause the video now to have a go at today's talk task.

Okay, I'm going to come back onto screen so you can see me.

And I'm just going to shimmy off to that where there's space for me then.

So, oh no, now there isn't.

Now we're going to be discussing so I'm just going to cut that part off there.

So you can see all of these and the bar models here.

So let's start off by looking at the term twice as many.

Here you can see this bar model really appropriately looks at the term twice as many.

You can see here, the main bar's been split into two and you can see here, that we've got twice as many.

This time, I want to look at the word three times as many.

So I've got a bar model that's been split into three and I'm looking at this part here, which tells me three times as many.

Now I'm going to look at one quarter of.

Ooh, one quarter of.

Now I need to find a bar model that has been split into quarters.

So I'm going to link that to this bar model here.

You can see it's been split into quarters.

Double then.

I know that double well I'm going to use this bar model here because I can see here, there's one part and double that gives me the two parts.

Half of.

Well, let's have a look.

I am going to also use this bar model because I can use my whole here and I can say half of my whole represents this much.

And last, but not least, I'm going to look at one third of.

Now I'm going to find a bar model that represents, it's just behind me the arrow, that represents something that's been split into thirds.

So this bar model here would represent that word here.

This term here, sorry.

Okay then, so going to move myself again so we can see our next problem.

So how would you describe this bar model? Let's have a look.

There are five, there were five, not even are.

There were five people on the bus.

Twice as many people get on at the next bus stop.

How many people are on the bus now? So we don't know how many people are on the bus now.

But what we do know is that there were five people on the bus.

So the known parts are the five people on the bus.

And the known parts of the fact that twice as many people get on at the next stop.

The unknown part is how many that is total.

So I'm going to mark on my five here.

I know that five people get on the bus.

I know that twice as many were on the bus, sorry, twice as many get onto the bus.

So this here is going to represent five.

This here is also going to represent five.

So I'm going to put this into my bar model so I can see them.

Now, I know that there's five here.

Five here and five here.

So do I know how many people in total were on my bus at the next stop? I now I do.

I know that 15 people are on the bus in total because 10 people get onto the bus now at the next stop twice as many.

So we have our five here and our 10 here.

So 15 people are now on our bus.

Mia baked 15, sorry, this is the next question.

Mia baked 15 cookies.

She gave one third of them to her brother.

How many cookies did she give to her brother? So we know how many she baked.

She baked 15.

So if I'm thinking here are my known and my unknown parts, I know she baked 15 cookies.

I know that one third of those cookies she gave to her brother.

Hmm, fairly fairly fair of Mia.

So let's put in that information here.

Here's our 15.

And now what we need to do is find out what that one third is.

So I've used some counters to show you today.

So I'm going to imagine these counters are cookies.

Unfortunately they're not, but if they were, I probably would've eaten them.

So we're going to put in my counters as cookies.

So I'm going to put in 15 one, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15.

Can I keep going? No, unfortunately Mia didn't bake any more extra cookies for Mrs. Crane.

So in each of the third, so I'm hoping she gives me all of this in each of the thirds, you can see the amount of cookies that Mia had to divide them into before she gave her brother a third.

But how many cookies did she give to her brother? She gave him five cookies because you can see here that if you split that into three groups here, each group represents five.

Oops.

But then, it is now time for your independent task today, which is going to be using bar models the solve equations.

I'm just shooting myself up so you can see very clearly.

So question one, what I'd like you to do for each question is solve the word problems using the bar models to represent them.

You'll have three questions.

This question, this one here, and question three.

Remember you can use counters to help you just solve them.

Look really carefully at the bar models and read the question where you have to.

So please can you now pause to complete your task.

Don't forget to resume it once you're finished so that it can go through the answers all together.

Okay then I'm going to put myself back on the screen so you can see me as we go through the answer.

So question one, there are six sweets in the red bag.

There are twice as many sweets in the blue bag.

How many sweets are there in the blue bag? So I'm going to do six here because I know there's six in the red bag.

And there's twice as many in the blue bag.

So I need to put in two times by six.

And I know that two times by six is equal to 12.

So I can put 12 into my model here and 12 in here.

You could have drawn them in here to help you.

You could have drawn them in here using your counters as well.

Question two.

There were 20 passengers on a bus, half the passengers got off the bus.

How many passengers were still on the bus? So I know here that half so divided by two got off the bus.

So I also know if my whole was 20, my whole 20 has been divided into two groups.

I know that 20, half of 20 is 10 so that I know that each group represents 10.

So there's going to be 10 passengers left on the bus.

I can put 10 in here to show that.

And question three.

The postman has some letters in a stack on Monday morning.

I hope he's got delivery for me.

He delivered one quarter of them to the first house in the afternoon.

Three letters were delivered to the first house.

How many letters were there in the postman's stack on Monday morning? So we don't know how many there were in total, but the information we do know is that three were delivered to the first house.

And we know that was one quarter, which is one, two, three, four, one quarter of the amount.

So I can times it by four to give me my answer.

So I'm going to do three.

So imagine this is worth three here and there are one, two, three, four of them to work out our whole three times four is 12.

So I know that there were 12 letters in the postman's stack on Monday morning.

If you'd like to please ask your parent or carer to share your work from today on Twitter, by tagging @OakNational and using the hashtag LearnwithOak.

Fantastic work today, I've been super impressed, especially when you've got to look really carefully at what those parts and those wholes represent and what that bar model really represents.

Does it represent, is it got two parts? We've got three parts, or is it about four parts? Don't forget to complete your quiz before you finish today's lesson.

Hopefully I'll see you again soon for some more math.

Thank you and goodbye.