Lesson video

Hello, I'm Mrs. Cayley and I'm going to help you with today's lesson.

So in today's lesson we will show one more and one less than a number using representations.

So let's have a look at today's lesson outcome.

Here's the outcome of today's lesson.

I can use representations to show that the number before a given number is one less and the number after a given number is one more.

Here are keywords for today's lesson.

Can you repeat them after me? One more, your turn.

One less, your turn.

Before, your turn.

After, your turn.

Well done.

You might have seen these words before, so one more means that it is one more in the count.

It's the next number in the count.

It comes after a given number in the count.

One less is a number that comes before a given number in the count.

So it comes earlier in the count.

A number that is before another number comes earlier when you count and a number that is after a given number comes later when you count.

Let's have a look at today's lesson outline.

So today we will show one more and one less than a number using representations and we'll start off by looking at one more and then we'll move on to one less.

Here are some children that are going to help us in today's lesson we've got Andeep and Laura.

Let's say the number words in order.

We're going to start with zero.

Can you say them after me? 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

That's all the numbers up to 10.

Can you say them again and show them on your fingers this time? Are you ready? Start with zero.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

There are 10 fingers on our hands.

Let's say the number words in order again.

Let's start with zero.

This time you'll see some cubes to represent each number.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Can you see the numbers getting bigger and bigger? It's like a staircase.

Perhaps you could make these with some cubes if you've got any.

Watch what happens and think, what do you notice? So Laura is looking at the cubes.

I wonder what you notice.

We're going to start with zero.

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

There are 10 cubes altogether.

What did you notice as we counted the cubes? Laura noticed that each number is one more than the one before.

So can you see the extra one more cube? The red cube has been added to each one to make the next number.

We add one more cube each time.

So Andeep is going to help you now.

One is one more than zero.

Two is one more than one.

Three is one more than two.

Four is one more than three.

Five is one more than four.

Six is one more than five.

Seven is one more than six.

Eight is one more than seven.

9 is one more than 8 and 10 is one more than 9.

Andeep has notice that each number is one more than the one before.

So one is made up of zero and one more.

Two is made up of one and one more.

Three is made up of two and one more.

Four is made up of three and one more.

Five is made up of four and one more.

Six is made up of five and one more.

Seven is made up of six and one more.

Eight is made up of seven and one more.

Nine is made up of eight and one more.

10 is made up of 9 and 1 more.

Each number is one more than the one before.

We can represent this as a bar model.

So here's a bar model showing five.

Five is made up of four and one more.

Five is four and one more.

Four is three and one more.

Three is two and one more.

Two is one and one more.

And we can see this on the bar model.

Let's check your understanding.

Have a look at the towers of cubes.

Can you find the one that's showing five cubes? Five is made up of something and one more.

Five is one more than something.

So there's five.

Have a think about which number might go in the gap.

Pause the video and have a think.

That's right, five is made up of four and one more.

Five is one more than four.

Let's check your understanding again.

Two is made up of something and one more.

Two is one more than something.

There's two cubes.

See if you can think what number goes in the gap here.

Pause the video while you think about it.

That's right, two is made up of one and one more.

Two is one more than one.

Let's check your understanding again.

Four is made up of something and one more.

Four is one more than something.

Here's four cubes.

Pause the video while you think about what the answer might be.

That's right, four is made up of three and one more.

Four is one more than three.

Let's check your understanding again.

One is made up of something and one more.

One is one more than something.

Here's one cube.

What do you think the answer might be? Pause the video while you think.

It's right, one is made up of zero and one more.

One is one more than zero.

Here we've got some 10 frames.

I can see we've got 0 counters on the first 10 frame and 1 counter on the next 10 frame.

Each number is one more than the one before.

So if we add one more counter on, we'll find the next number, won't we? So if we add one more counter on, we'll find one more.

So one more than zero is one.

One more than one is two.

Laura has noticed that we add one more counter each time.

Andeep said, "Each number is one more than the one before." Here we've got the numbers 2, 3, 4 and 5 on the 10 frames.

Each number is one more than the one before.

So when we add an extra counter, we're going to find out one more.

So one more than two is three.

One more than three is four.

One more than four is five.

And one more than five is six.

We can keep going with larger numbers.

So here we've got the number 6, 7, 8, and 9 on the 10s frames.

Each number is one more than the one before.

So if we add one more counter, we'll find one more.

So one more than six is seven.

One more than seven is eight.

1 more than 8 is 9 and one more than 9, it's 10.

Let's check your understanding.

The first one says one is one more than? That's right, it's zero.

One is one more than zero.

Two is one more than? That's right, two is one more than one.

Three is one more than? Three is one more than two.

Well done.

Four is one more than? Yes, four is one more than three.

Five is one more than? It's one more than four.

And six is one more than? That's it, six is one more than five.

How did you get on with those ones? Laura said, "We add one more counter each time." Andeep said, "Each number is one more than the one before." Here's a task for you to have a go at.

Can you complete the table, colouring to show one more.

So you can colour the cubes to help you find one more.

So one is one more than, hmm? Two is one more than, hmm? Three is one more than? Four is one more than, hmm? And five is one more than, hmm? You could try making this with cubes to check.

So pause the video while you have a go at your task.

How did you get on with the task? Did you complete the table and colour the cubes to show one more? So one is one more than zero.

Two is one more than one.

Three is one more than two.

Four is one more than three and five is one more than four.

I can see from the cubes we've got the one more cube has been coloured in red and the rest of them are yellow.

Did you try it with real cubes as well? Let's move on to the second part of the lesson.

We'll be finding one less.

Let's start by counting backwards.

This is going to help us to find one less than a number.

Let's start at 10 and count backwards.

Can you do it with me? 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.

Let's try it again with your fingers this time.

Can you do it with me? 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.

Well done.

It's always good to practise counting backwards as well as forwards.

If we take a cube off a tower of cubes, the number becomes one less.

So here's 10 cubes and if we take the red one off, it's going to become nine cubes.

Here's nine cubes again and if we take one cube off, it will be eight cubes.

Here's eight cubes, if we take one cube off, it will be seven cubes.

Here's seven cubes, if we take one cube off, there'll be six cubes.

Here's six cubes, if we take one cube off, there'll be five cubes.

Here's five cubes, if we take one cube off, there'll be four cubes.

Here's four cubes, if we take one cube off, there will be three cubes.

Here are three cubes, if we take one cube off, there will be two cubes.

Here are two cubes, if we take one cube off, there'll be one cube.

Here's one cube, and if we take one cube off, we're left with zero cubes.

So as you take one cube away, the number will become one less.

Each number is one less than the number that comes after it.

So here's zero, one cube, two cubes, three cubes, four cubes, five cubes, six cubes, seven cubes, 8 cubes, 9 cubes, and 10 cubes.

So each number is one less than the next one.

Zero is one less than one.

Laura said, "Just as we can say one is one more than zero, we can say zero is one less than one." One is one less than two.

Can you see that on the cubes? "Just as we can say two is one more than one, we can say one is one less than two." Two is one less than three.

"Just as we can say three is one more than two, we can say two is one less than three." Three is one less than four.

"Just as we can say four is one more than three, we can say three is one less than four." Four is one less than five.

"Just as we can say five is one more than four, we can say four is one less than five." Five is one less than six.

"Just as we can say six is one more than five, we can say five is one less than six." So if we know one more than a number, we can work out one less as well.

Six is one less than seven.

"Just as we can say seven is one more than six, we can say six is one less than seven." Seven is one less than eight.

"Just as we can say eight is one more than seven, we can say seven is one less than eight." Eight is one less than nine.

"Just as we can say nine is one more than eight, we can say eight is one less than nine." 9 is one less than 10.

"Just as we can say 10 is one more than 9, we can say 9 is 1 less than 10." So if we know one more than a number, we can work out one less than a number.

Let's check your understanding.

Three is one less than mm? Look at the towers of cubes and decide what number three is one less than.

That's right, three is one less than four.

I can see on the cubes that three is one less than four.

Let's check your understanding again.

One is one less than, hmm? Pause the video while you think about this one.

That's right, one is one less than two.

Now see on the cubes that one has got one less cube than two.

Let's check your understanding again.

Four is one less than, hmm? Pause the video while you think about this one.

That's right, four is one less than five.

I can see on the cubes that four has got one less cube than five.

Let's check your understanding again.

Zero is one less than, hmm? Look at the picture while you decide.

Pause the video and think about this one.

That's right, zero is one less than one.

I can see that zero has got one less cube than one has.

If we take one counter off, the number becomes one less.

So earlier we were finding one more by putting an extra counter on.

Now we are taking a counter off to find one less.

So six, if we take a counter off, six becomes five.

So five is one less than six.

Now we've got five counters and if we take one counter off it becomes four.

So four is one less than five.

Here we've got four counters and if we take one counter off it becomes three.

So three is one less than four.

And at the bottom there we've got three counters.

And if we take one counter off it becomes two because two is one less than three.

Now we've got two counters and if we take one off it becomes one counter because one is one less than than two.

At the bottom there we've got one counter.

And if we take one counter off, we've got zero because zero is one less than one.

Let's check your understanding.

Zero is one less than, hmm? Pause the video while you think about this one.

That's right, zero is one less than one.

I can see on the 10 frames that zero has got one less counter than one.

Let's check your understanding again.

One is one less than, hmm? Pause the video and use the 10 frames to help you think about this one.

That's right, one is one less than two.

I can see that one has got one counter fewer than two.

Let's check your understanding again.

Two is one less than, hmm? Pause the video and use the 10 frames to help you.

That's right, two is one less than three.

If you start with three counters and you take one counter off, you'll have two counters.

So two is one less than three.

Let's check your understanding again.

Three is one less than, hmm? Pause the video and think about this one.

That's right, three is one less than four.

So if we take one counter off from four, we'll end up with three.

Let's check your understanding again.

Four is one less than, hmm? You can use the 10 frames to think about this one.

That's right, four is one less than five.

If we take one counter off from five counters, we'll be left with four counters.

"What do you notice?" Andeep said, "Each number is one less than the one after." Here's a task for you to have a go at.

Can you complete the table colouring to show one less? So this time you can use the cubes to help you work out one less than the numbers.

So zero is one less than, hmm? One is one less than, hmm? Two is one less than, hmm? Three is one less than, hmm? And four is one less than, hmm? And you could try this with real cubes as well.

So pause the video and have a go at your task.

How did you get on with your task? Did you complete the table, colouring to show one less? So I can see from here that zero cubes is one less than one.

One is one less than two.

Two is one less than three.

Three is one less than four and four is one less than five.

How did you get on with that one? If you compare this to the previous task where you were finding one more, you might notice that the numbers have swapped round.

Well done everyone.

We've got to the end of our lesson.

So today we were showing one more and one less than a number using representations.

This is what we found out.

The number before a given number is one less.

The number after a given number is one more.

A variety of representations including a staircase of blocks can be used to highlight one more and one less.

So you can always use cubes or counters to check.

Well done everyone.

See you next time.