Lesson video

Hello and welcome to this lesson, finding one more or one less using representations.

By this end of this lesson, you'll have used lots of different representations to show one more or one less than a number.

So today's lesson is split into two parts.

First part, we're going to make representations to show one more and one less.

And in the second part we are gonna carry on making them but we're also going to say them, draw them.

So we've got lots of different ways to show one more and one less.

Now then, when you're thinking about numbers from zero to 20 we can represent them in lots and lots of different ways.

We can represent them using cubes or counters.

We could use a bead string or a tens frame.

And if you're doing this at home, you could use Lego blocks or other objects that you can find.

To start off, we're gonna use a bead string.

Have a look at the bead string I put on the screen now, or you could use a bead string on the table in front of you.

Number is represented by the bead string.

Let's count the beads to find out.

Are you ready? 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19.

So there are 19 beads on the bead string.

So that bead string is representing the number 19.

Now then, let's have a think.

What is one more than 19? What is the next number after 19? Let's look what the bead string looks like.

So you can see there's one more bead on the bead string.

So one more than 19 would be? Yes, that's right.

It would be 20.

Well done.

And if we want to make one less than 19, then our bead string is going to have one less bead on it.

So we're gonna say it's one less than 19, which is the number before 19.

So one less than 19 would be? 18.

Well done.

Now then, we can also use cubes and make a staircase shape to represent the idea of one more and one less.

So on the screen at the moment, how many green cubes can you see? Can you count them? So 1, 2, 3, 4, 5.

So we've got five cubes on the screen.

And to make it into a staircase, you're gonna add one more cube and one less cube.

So if the mid row is five, one more than five is six, and one less than five is four.

So I've made a staircase here and you can see how the stairs go up.

So we've got our four cubes.

One more than four is five.

One more than five is six.

So you can see the staircase image of one more each time.

So now let's make some sentences to describe these towers.

So we could say that six is one more than five.

And you can see here we've got our six is one more, and there's our one more than five.

What else could you say? You could say that five is one more than four or you could say that four is one less than five and five is one less than six.

Let's look at another example.

So let's have a look at these towers.

So how many blocks are in the towers? What do you notice? We can see the staircase image, can't we? So we know that each tower is one more than the tower before.

So how many cubes are in the orange tower? Let's count them and see.

We've got 1, 2, 3, 4, 5, 6.

So one more than six would be seven, and one more than seven would be eight.

So we know they represent six, seven, and eight.

What else do we notice? We could say that seven is one less than eight and six is one less than seven.

So it's using those sentences to describe the different towers that we're making.

Now then, what do you notice about these? Can you come up with some more and less sentences? You can see the first one is 10.

So pause the video now and make your own sentences to describe the three towers.

So what sentences did you come up with? What did you notice? Did you think of 12 is one more than 11? Or you could have 11 is one more than 10, or did you find some less sentences? You could have had 10 is one less than 11 and 11 is one less than 12.

What about these ones here? So we can see the staircase image on the side.

So we know that the first tower is 13.

So the next tower is one more than 13, which is, yes, 14, and one more than 14 is, yes, it's 15.

Pause the video now so you can make up your own comparative sentences using more and less.

So which sentence did you come up with? Did you find 14 is one more than 13 and 15 is one more than 14.

And for the less sentences you could have 13 is one less than 14, and 14 is one less than 15.

Now we're looking at task number one.

Now you can see there's a big staircase image, and this shows all the numbers from one through to 20.

And you can see the staircase image going up just like the stairs if you've got a staircase at home or that you've seen when you've been walking around town.

So what I want you to do is looking at the next door numbers that are 13 and 14 and 14 and 15, and describe different steps that you're making.

So you could choose two numbers like 14 and 13, in which case you'd say 14 is one more cube than 13 and 13 is one less cube than 14.

So what I'd like you to do now is make up five different sentences to describe different steps.

If you want, you could actually make the staircase steps with the cubes and then you can count them and then describe them as you're making them.

Pause the video now.

So which two nextdoor numbers did you choose to make your sentences about? I chose five and six.

So I was able to say that five is one less cube than six and six is one more cube than five.

And we can see the stair, staircase image here to show that one more and one less difference.

Which numbers did you choose? You could have chosen 11 and 10 and you could have then said 11 is one more than 10 or 10 is one less than 11.

Other numbers you could have chosen could be 16 and 15 and you could say 16 is one more than 15 and 15 is one less than or one fewer than 16.

We've now finished the first part of our session today.

So we've been making representations using the cubes and the staircase image to show one more than and one less than.

So we're now moving into the second part of our session today, where we're going to be making, saying, and drawing different representations to show one more and one less.

So let's look at the number track.

Here it shows the numbers from zero through to 20.

Now the number we're going to start thinking about is number 12.

And you can see I represented number 12 using some cubes.

So we could count the cubes and we'd see there are 12 cubes.

Now we're thinking about one more and one less.

So we could say that 12 is one less than 13.

So what would that mean about 13? What could we say about 13 and 12? There's our 13.

So we could say that 13 is one more than 12, and we think about we've got 13 and we've got 12.

So let's think the other way.

So what's one less than 12? One less than 12 would be 11.

So we could say that 11 is one less than 12.

So there we have our three numbers that are next door to each other.

And if we think about the staircase, we've got 11.

One cube more than 11 would be 12.

One cube more than 12 would be 13.

Let's look at another example.

So here we have some cupcakes.

So we can see cupcakes.

There are 14 cupcakes.

So 14 is one less than 15.

So here we have 15 cups and we'd say then if 14 is one less than 15, then 15 is going to be one more than 14.

If you go back to 14 again, we could say that 13 is one less than 14 or we could say 14 is one more than 13.

You imagine that staircase image again.

You'd have 13.

One more than 13 would be 14, and one more than 14 would be 15.

Hey, let's look at another one.

So this time we're thinking about the number 16.

So if we're thinking about 16, one more than 16 would be, yes, 17, and one less than 16 would be, yes, 15.

So let's look at how this works.

So we've got our 16 and we can say 16 is one less than 17, and there's our 17 beads.

So 16 counters, that's representing 16.

And the 17 beads is representing the 17.

So we can see there's one more.

17 is one more than 16.

And if we think the other way, what is one less than 16? So 15.

So 15 cups.

So 15 is one less than 16.

Well done.

Now then we're gonna look at some bead strings here.

Now you can see the bead strings are representing different numbers.

We need to count them to see if they're in the right order.

We want them each one to have either one less or one more.

So if we look at the one on the left, how many beads are in the bead string on the left? Would you like to count them? So, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.

Now then if we look at the 15 there, we've got the one next to it.

Can you see there's one bead more? There's that white bead and it's one more.

So one more than 15 would be, yes, 16.

And if you look at the next one, there's another, so there's two more, or one more than the one before.

So one more than 16 would be 17, and the final one has one more.

So one more than 17 would be 18.

So we say, are the beads in the right order? And we say yes.

Yes, because they show 15, 16, 17, and 18.

Now then, we'll have a look at the next slide.

So we can see are the beads in the right order? So pause the video now so that you can count up the beads and then we can see if they are in the right order.

Okay, so how many beads in the far bead string? Yes, there are 13.

So does the one next to it have one more? No, it doesn't.

It has one less.

So no, they aren't in the right order.

They show 13, 12, 14, and 15, because 13 is one more than 12, so it should come after 12.

So those two are the wrong way round.

Let's look at one more.

So are the beads in the right order? Pause the video now so you can count them up.

So how many beads are in the first bead string? Yes, there are 11 beads in the first bead string.

How many beads are in the second bead string? That's right, there's one more.

There's 12.

And how many are in the third bead string? 14.

Oh, that's not right, is it? Should be 13 next.

So those last two are the wrong way around.

Did you spot that? So the answer is that they show the numbers 11, 12, 14, and 13.

So 13 is one less than 14, so it should come before 14.

So those last two are the wrong way around.

Okay, now for the final part of this session we've got a practise activity for task two.

So if you look at image you can see there's a bead string in the middle.

So you're gonna have this sheet and the next slide as two worksheets that you're going to work on.

And what I want you to do, round up the number of beads represented in the middle column, and then I want you to make a model that has one less cube and one more cube.

There's a few sheets for you to try.

If you're working at home you could make a model using Lego cubes.

Pause the video now.

Let's think about the models that we've made to represent one less than and one more than.

I've used some cubes to represent them.

So I looked at that middle one, which was 11 beads, and using my cubes I've made a model to represent one less than 11.

So I needed 10 cubes.

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

So I used 10 cubes because I knew that 10 is one less than 11, and I used cubes again for one more.

So I thought that 12 is one more than 11.

So I've got 12 cubes here.

So 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, because 12 is one more than 11.

Here are the examples on the slide.

And you can see these are using the bead strings.

So in the middle we've got our 11, and then if we look at the one less, we can see one bead less, which is our 10.

And then the other side, we've got one more and we can see that red bead, that extra red bead.

So that one more red bead, which represents the number 12.

So we can see 10, 11, and 12.

Let's look at the second one.

So in the middle here we've got a representation of the number 16.

So if we're thinking about a model that is one less than 16 it will have yes, 15, 15 beads or 15 cubes, and one more than 16 would be 17.

Yes, 17 beads or 17 cubes.

So you can see the examples here.

So we've got our 15.

One more than 15 is 16, and one more than 16 is 17.

Well done.

Now for the final part of this task, we're going to be talking, saying some sentences to describe the different numbers, and we're gonna draw a model, then we're gonna make a model.

So you've got three things to do.

So first of all, you're gonna read out the sentence to your partner.

So the sentences are, seven is one less than eight, eight is one more than seven, and six is one fewer than seven.

So you're thinking about those numbers and I want you to draw a picture to show them.

And then I want you to make a model to explain the sentences.

Your teacher will provide you with some paper and some resources like cubes or Lego bricks so that you can have a go with this activity.

So pause the video now.

So how did you get on? Were you able to think about the numbers 6, 7, and 8, or did you use some other numbers? Here's the example I had.

So first of all, I read out the sentences.

So seven is one less than eight, eight is one more than seven, and six is one fewer than seven.

Then I've drawn a little picture with my 5, 6, 7, 8, and 9.

So I can see where the 6, 7, 8 fits and then I could have drawn a picture using the cubes.

Then I've made a model using the cubes.

So you can draw any picture you like to represent it.

You might have drawn a picture of the bead string and then used the beads to make the representation.

Well done.

So in today's lesson we've been finding one more or one less using a variety of different representations.

We used that staircase image and we used the bead string and we used some cubes.

There's lots of things that you could use to represent each of those numbers.

This is the end of the lesson.

You've worked very hard today and I look forward to working with you again soon.

Bye.