Lesson video

Hello everyone, I'm Miss Brinkworth.

I'm going to be going through this lesson with you today.

Shall we get started? So what we're going to be doing today is we're going to be using bar models to solve word problems. So actually, today's lesson's a little bit different to normal.

This is because what we're going to be doing is we're going to be looking at how bar models help us and we're going to be looking at real detail about the different kinds of bar models we can draw but we're not actually going to be answering the questions.

Today is all just about how we can use bar models to help us answer them.

So, shall we get started? So, our agenda for today is we are going to have a think about recognising what we mean by multiplication and division questions.

And we're then going to think about matching bar models to questions.

So, which bar models help us answer which questions? We're then going to think about the fact that there are different bar models and how we can make sure we're using the most efficient ones to help us.

And then there will be some independent work at the end for you to have a go at answering on your own.

So, all you're going to need is a pen or pencil and some paper, a big smile will get you a long way as well but pause the video here and get what you need.

Okay, let's get started then.

So here's a little bit of a warm-up for you.

Can you match up the purple statements with the pink questions? So which of these match which ones are asking the same thing? Pause the video and come back for the answers when you're ready.

Let's see how you got on.

So it's important that we recognise that when questions are asking us about multiplication or division, they don't always use the same words and it's not always nicely written out, like those pink multiplication and division questions there.

Sometimes it's down to us to work out that the question requires multiplication or division.

So when you see a question like twice as many as 6, what does that mean? Twice as many, you've got 6 twice.

You got twice as many as 6.

So that question is actually 2 x 6.

You might hear in normal life people saying, "Oh, I've got twice as many as that", or "They had twice as many as me." So that's the sort of vocabulary that people use when they're using multiplication in a real-life situation.

But what they're doing when you see the pink statement is 2 x 6.

What about double 9 then? Double again means that you've got two of something, you've got two 9s.

So, that one's 2 x 9.

A third of 12, a third of 12.

12 split into 3, so 12 divided by 3.

10 times greater than 4.

10 times greater than 4 is 4 times by 10.

And half of 14 or when we half something, we split it in two equally.

So 14 divided by 2.

If you got all of those right, really, really well done.

You understand a lot about the vocabulary of multiplication and division.

If you didn't quite get all of those right or you found that quite tricky, don't worry.

We're going to be looking at some of these vocabulary in quite a lot of detail in today's lesson.

Okay, here's a question then.

Robin Hood shot his arrow 3 times as far as the Sheriff.

The Sheriff shot his arrow 20 metres.

How far did Robin Hood's arrow go? Now here are two bar models that could be seen to both answer this question but one is more appropriate than the other for this question.

What I like to do when I see a word problem is to really picture this in my head.

So we've got Robin Hood and we've got the Sheriff and they're having an archery competition.

The Sheriff shot his arrow 20 metres, that's quite a long way, but Robin Hood shot his 3 times as far.

So it's going a really, really long way.

It's going 20 x 3.

Now, which one of these bar models do you think most accurately would help us answer that question? Well, the thing about bar models is they can do two different jobs.

This one here shows a whole and it's got the question mark underneath a bar, which is showing the whole.

And then it's got 20 and it's showing us that we need to do 20 x 3 will give us the whole.

The other one has not got a bar showing a whole amount but we have got 3 sections each, which represent 20.

Now the second one is actually the most appropriate for this question.

That's because this question isn't about part and whole.

They both got a separate score.

It's not about the Sheriff's being part of Robin's.

They're separate things.

So what we're talking about here is more than or greater than, it's 3 times as many.

So the bar model on the right is more appropriate to help us answer this question.

And this one here would be more appropriate for a different type of question.

Maybe one like: there were 3 bags of sausages.

Maybe one like: there were 3 bags of sausages.

Each bag of sausage had 20 in, how many sausages is that in total? Then we would be looking for a whole and that bar model there would suit that type of question.

Let's have a look at another one.

Maid Marion collects 6 gold coins.

Friar Tuck collected 3 times as many.

How many did Friar Tuck collect? Then we've got two similar bar models here to the one that we saw before.

And again, we can see that one at the bottom is showing a whole, a bar which represents the whole and then 6 as one part of that whole.

The one at the top doesn't show us a whole but it does show us, again, that we have 3 sections and each of them represent 6.

So for this question, this is the appropriate bar model.

That's because again, these two quantities, the amount that Maid Marion collected and the amount that Friar Tuck collected are separate.

It's not part and whole, it's 3 times as many, it's greater than.

So that bar model is more appropriate to this question.

Okay, have a look at this one and just have a think about which of the bar models you think suits it better? Maid Marion climbed 12 metres up a tree.

Robin Hood only climbed half as high.

How far did Robin Hood climb? The bar models are similar but have a think about which one you think is most appropriate? When you're thinking about appropriateness, all you need to think about is: which one is going to help me answer that question better? That's all we mean.

And hopefully, you can see that it's this bar model that's more appropriate to this question.

Again, the amount that Robin Hood and Maid Marion climbed up the tree is not a part and a whole.

They don't have that relationship.

They're different quantities and we comparing them.

So what they're saying is that Robin Hood is only half of Maid Marion's climb.

So it's that bar model shows that relationship, more so than that one.

Okay, pause the video here, read the question, and decide which bar model you think is best suited to that question? How did you get on? So, it says Robin Hood collected 14 coins 2 days in a row.

How many did he collect in total? Well this time, this bar model is not quite as appropriate as this one.

That's because we are looking for the whole.

The question says: how much did he collect in total? So we do need to get 14 and times it by 2 to get a whole answer.

And that bar model shows what the question is asking us in a little bit more of an appropriate way.

Okay, so bar models can show part/whole relationships.

And they do that like this where we have our bar representing a whole and bars or bar representing a part, depending on what we know and what we're looking for.

They can also show times, greater or more than.

So, that would look more like this.

So these bar models are not completely dissimilar but it's really important to think about which ones are most appropriate for the type of question being asked.

Okay, pause the video here and have a go at the independent task.

You don't need to solve any of these multiplication questions, just have a think about which bar model you think would help you solve them.

Come back and we'll have a think about our thoughts together.

Well done! Well done for trying that independent task.

Let's have a look at how you got on.

So, like I mentioned in the lesson, some bar models show part and whole.

A relationship where the question is saying, this is the part, what is the whole? Other ones show a question where we're saying, they got 3 times greater or 5 times greater or 5 times more than, okay? So some where we would want the whole are these ones.

These show part and whole; these ones show a question where we're thinking about something being greater than.

Well done as well if you had a go at this question where we're matching up the question with the appropriate bar model.

So, the first question said Robin had a score of 24 in the archery competition.

The Sheriff's score was only 1/3 as much.

What was the Sheriff's score? Well done if you could see that this bar model suits that perfectly.

The Sheriff's score is not a part and it's not that Robin's score is the whole as such.

It's not that relationship in this question.

So we don't have that bar representing a whole.

Again here, the Sheriff fired 3 arrows in the time given.

Robin Hood fired 8 times as many.

It's not that Robin Hood's amount was the whole and that the Sheriff's was the part, it's just that we do know that we have got 8 lots of 3 to work out that answer.

And then finally this one where we do have a part/whole model and that's because we're looking for how much he collected in total? Really, really well done if you got those questions right.

That's fantastic! If you'd like to share your working out with us for today's lesson, that would be great! Please ask your parent or carer first to share your work on Instagram, Facebook or Twitter tagging @OakNational and #LearnwithOak.

Really well done on today's work, everybody.

Well done, enjoy the rest of your learning today.

Bye bye.