Lesson video

Hello again, and welcome, year three This is the fifth lesson in our first unit on fractions And today's lesson is all about describing unit and non-unit fractions.

In order to do that, we do lots of exploratory ideas Lots of opportunities to play around with fractions and see the relationships between fractions so it should be a lot of fun.

Okay, let's get going! Now, in this lesson to help us to explore a bit more you're going to need some paper, a pencil, also, if you can get some resources to help you, things like Lego are particularly good for this Then please do get some of that And the other thing is we're going to be using something called Cuisenaire rods today.

Now you might have used these already in school but I very much doubt you're going to have them to hand at home So if you don't, you could, I'll provide a resource, You could try and print them out, But the best way of doing it is to go on to the Internet and search for online Cuisenaire rods and you'll come up with some interactive Cuisenaire rods that you can use and you can copy and duplicate to move around and really explore it in more detail.

And that's the best way of doing it, okay? I'll give you a few seconds so you might want to pause, get yourself another tab open so you can have a look at those, and then when I pause you can go back to it.

Before we get started, make sure you have completed that knowledge quiz.

It's a bit of a warm-up, then.

We've been looking at unit fractions so I'm going to give you twenty seconds to try and write down as many unit fractions as you can remember.

If you can, also draw a diagram, to prove your understanding of them just that last time, okay? Pause the video.

and.

go! Right, okay, we're back.

How many did you get? Excellent.

Right, let's carry on.

Let's go through the star words, nice and quickly.

My turn, your turn.

Part.

Whole.

Fraction.

Equal.

Tenth.

Ninth.

Divide.

Okay, so these are some of the words we'll be using today.

Now, I said we're going to use Cuisenaire rods.

This is an example of what some Cuisenaire rods look like.

So they're just like big bars really But all the bars are related to each other.

So we can compare and talk about how they are the same or different to each other.

Have a look at these two bars.

How would you describe the relationship between the yellow and the orange bars? I want to think, how many times would the yellow bar go into the orange bar? If you want to, take a second to pause and try to describe this.

So, two yellow bars are the same length as the orange bar.

The orange bar, therefore, is two times longer than the yellow bar.

But the yellow bar is half of the orange bar.

So lots of vocabulary, and lots of language that we are using there to help us to describe the relationship between the two parts.

So if you need to, go back and pause and think about can you practise using that language? If you don't believe me, I've proven there are two yellow bars for every orange bar.

So that proves the orange bar is twice as big As one yellow bar.

Okay, so play around with that.

If you want to, maybe get them and have a look at them.

Now here's two more bars.

Now without me giving you any information, I've given you some spaces down at the bottom to give us a bit of a sentence structure to help us.

Pause the video, can you talk and describe the relationship between the orange bar and the red bar? Or, the red bar and the orange bar? If you want a bit of a clue with this, to help us along a little bit, does that help? Pause the video and see what you can do.

Okay.

So what did you come up with? So from this, we can see that 1, 2, 3, 4, 5 red bars are the same length as the orange bar.

So the orange bar must be five times as long as the red bar.

So one of these red bars, the orange bar is five times as long as it.

So that must mean, thinking about fractions, if it's five times as long, then the red bar is one-fifth of the orange bar.

Because we can get five of them into the orange bar.

So there again, we're starting to use our language and really build up our language to be able to compare the relationship between bars.

Now, I want you to try and explore this a bit in your house.

So, I want you to go around.

So you might want to draw some of your own bars.

If you've got squared paper, it makes it particularly useful.

Or, use some objects that you've got in your house such as Lego, or remote controlled cars, or anything else, any other toys that you've got.

And see if you can start comparing them against each other.

Is there anything which is twice as big as another object? Is there anything which is half the size of another thing? Is there anything which is one-quarter of something? So go around your house, your bedroom see what objects you can find.

Can you describe the relationship between them? Pause the video now and when you're finished we'll come back and deepen our understanding a little bit more.

Okay, how did you do? Hopefully you've been able to use that key vocabulary and the language structures to help us to describe the relationship between the different objects so let's carry on.

Here we have got all the Cuisenaire rods.

Now I'm going to provide this in a resource so if you pause the video and click on you can print your own version if you do have a printer or you can get it up and be able to see it.

Now, what other relationships can you describe within these bars? What can you see? So can we describe anything compared to anything else? I would say, this yellow bar like we said is about half of the orange bar.

I think this one I wonder how many times this goes into the green bar.

It looks like once, twice, three times.

So possibly, pause the video, and have a bit of time thinking and what relationships can you see there? How can you explore these relationships? Pause the video and then come back.

Okay.

Now we have said that you might have seen when you were going through and describing relationships that actually, we quite often describe different things as half.

Now, we described all of these different bars as half at some point.

And does that mean they're all the same as each other? How can all of them be half? Well the answer is if you think back to our first lesson together, we don't always have the same whole.

So the relationship, it's very important to think about what is the whole that we're dealing with? If the whole is one thing, then we could have a half.

So this green could be half of something, but it could also be a third of something.

So let me go back with an arrow I can see that this white rod here is half of the red rod.

But the white rod is also one-third of the green rod.

And actually, this white rod is one-tenth of the orange rod at the bottom.

If you don't believe me, then have a go explore go onto the Internet and have a look at that online resource and test it for yourself.

Let's think a little bit deeper then.

Have a look at these two bars.

Now when we look at this whole bar How many of these red bars can we fit into the whole bar? So, what is the value of each of these red bars? And how could I write that as a fraction? Hopefully, we're all able to say that if this is our whole then each of these bars is worth one quarter.

Now, if I had two of these bars, what would the value be? Would it still be one quarter? But if I have two of them, then it has a different value.

So our numerator suddenly might change.

Because you've got 1, 2.

So actually if I've two of these bars then actually if I write it as a fraction of two of the bars it's 1, 2 quarters.

Let's have a look at this example.

Now the orange bar is here.

What's the relationship between the orange bar and the white bars? Have a think and try and explain it.

Let's count together.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

So thinking about fractions, what fraction of the whole is each white bar worth? That's right.

Each bar is worth one-tenth.

So if we know that, can we then use that knowledge to help us to think about how much would two of the bars be worth? So we can now start to count in fractions.

So we've got one-tenth of the bar We have two-tenths if we have two of them.

We have three-tenths if have three of them.

We can start to add up and use our knowledge of fractions to help us describe the relationships between these bars.

Is there anything else you can spot that? You may pause the video and explain it to a friend.

Okay now a little bit further, I've got another one of my bars.

How can I describe in fractions, the size of the green bar? What can I use to help me? Well if I look down I can see that 1, 2, 3 of the white bars which we know as a value of three-tenths is the same as this green bar So I could describe this green bar as a value of three tenths of this bar.

Okay.

So we've done a little bit more explanation.

I've just taken a few specific examples for us to play around with.

Now our main activity today is very exploratory.

I want you to go away and have a play around with some of these Cuisenaire rods.

And see if you can find different relationships.

So I've given you an example there.

I've said that red bar is two-tenths of the orange bar.

So we can see here that I've got the red bar.

And I worked out and I was able to see when I went into my search that I can get five of these so it's two-tenths.

What I'd like you to do is have a bit of an explore.

See what you can find out.

See what relationships you can find between the unit and non-unit fractions using the bars below.

At this point, I'm going to ask you to pause the video and have a bit of a go at that.

Okay guys, well done.

Hopefully you've got lots of different ideas and you've been able to spot and identify lots of different relationships.

Where you have been able to, I hope that you've been able to then draw and label what you've found so it's really clear what you've been doing.

Okay that wasn't an easy lesson today, guys and it's just an introduction to us being able to describe the different relationships between fractions using those Cuisenaire rods.

Okay, well done today.

And make sure that you complete the final quiz before you finish the lesson.

Okay guys, goodbye.