Lesson video

Hello, my name's Mrs. Hopper and I'm really excited that we're going to be learning together in our maths lesson today.

Today's lesson is all about finding one less from a group with manipulatives and by counting.

So we're going to be concentrating on one less than today using some objects and then using our counting.

We've got lots of keywords in our lesson today.

We've got one less than and one fewer than, and we use them to mean about the same, but in different situations we use different ones.

So look out for those in our lesson.

And then we've got the number before.

So let's have a go at saying those words.

I'll have my turn and then you have your turn.

So my turn, one less than.

Your turn.

Well done.

My turn, one fewer than.

And your turn.

My turn, number before.

And your turn.

Well done.

So look out for those words as we go through our lesson today.

So there are two parts to our lesson.

In the first part, we're going to be finding one less than using manipulatives, so using objects that are around us.

So you might have some cubes or some counters that can help you with your learning today.

And in the second part of our lesson, we're going to be finding one less than or one fewer than by counting.

So let's get started.

We've got Jun and Sophia helping us in our lesson today.

Right, we've got a red traffic light here.

How many cars are there? That's right, there are three cars at the red traffic light.

Hang on a minute though.

The traffic light's gone to green.

How many cars are there now? That's right.

There are two cars now.

One car has gone away, and we can say that, because one car has driven away, there is one fewer car.

So there is one fewer car in our line at the traffic light, and there are two cars in that line.

So we had one fewer car, but we can say that one less than three is two.

So when we think about our numbers, we can say one less than three is two.

There were three cars.

One has driven away, and now we have two cars in our line.

There's one fewer car, but one less than three is two.

I wonder if you can say that.

I'll say it and then it can be your turn.

So my turn, one less than three is two.

And your turn.

Well done.

How many cars are there in this line? That's right, there are four cars.

I wonder if you counted or whether you could just see the four cars.

Let's look what happens now.

(gasps) How many cars are there now? One car's driven away again, hasn't it? There are three cars.

Yes, you're right.

There is one fewer car.

One car has driven away, one fewer car.

So there were four cars.

Now there are three cars.

So we can say that one less than four is three.

Can you have a go at saying that? I'll do it first and then you.

My turn, one less than four is three.

Your turn.

Well done.

So our car's driven away.

We had four cars, now we've got three cars.

One less than four is three.

I wonder if we can show that on our number track.

Let's have a look.

So there's my arrow pointing at four.

So that's to represent my four cars that I started with.

And then one less than four is three because one car drove away, so my arrows moved to three.

My number's got smaller.

One less than four is three.

So we can show one less than four with the beads as well.

So we wanna show one less than four.

So let's start with four beads.

So let's put four beads across on our top row.

So there we've got our four beads.

And just like the cars, when one car drove away, we're going to move one bead back to where it started from, so we can show one less than four with the beads.

Let's have a look.

So we've moved one bead back and now we've got three beads.

One less than four is three.

So can you show one less than six? Let's have a think.

We're gonna fill that sentence in.

One less than six is hmm.

So first of all, we need to put our six beads across.

So let's do that.

So there are our six beads moving across and we want one less than six.

So remember, with the cars, when we had one fewer car to find that one less number, the car drove away.

So let's move one of the beads away.

So one less than six is five, Well done.

Yes.

One less than six is five.

Let's have a look at that on our number track again.

So we can see our six beads there, and we're going to move one bead, and we're going to think about how the numbers change, how we move our pointer.

We're gonna start at 10, and we're going to count backwards.

So let's count back from 10.

Are you ready? 10, nine, eight, seven, six, five.

Do you see the bead move when we went from six to five? One less than six is five.

Time for you to have a go at one.

Have a look at what the pictures show and see if you can complete the sentence.

One less than hmm is hmm.

Pause the video and have a go.

So what did you see with the beads? I hope you saw that the beads on the left of the screen show the number eight.

We've got eight beads in our top row.

And the beads on the right of the screen show the number seven.

We've got seven beads showing.

So what can we say? We've got to fill that sentence in, one less than hmm is hmm.

So did you spot one less than eight is seven? We've moved one of the beads away to turn eight into seven.

So we've got one fewer bead.

One less than eight is seven.

Another chance for you to have a go.

I wonder if you can fill in the gaps here.

So we've got the gaps in different places.

So let's have a look at the sentences we're completing.

So the first one says, hmm, is one less than five.

So what number is one less than five? Second one says six is one less than hmm.

So six is one less than what number? And then finally, hmm is one less than six.

So what number is one less than six? You might have some beads to help you or some counters.

Now pause the video, have a go, and we'll look at them together.

So let's look at our top one.

We have to find the number that is one less than five.

Hmm is one less than five.

So I've got my five red beads there on the left of my top bar.

So let's have a look.

One less than.

We're going to move a bead across.

So let's have a look.

One less than five is four.

That's right.

So four is one less than five.

We've just turned the words around a bit.

Let's have a look at the next one.

So six is one less than what? Hmm, let's have a look.

We want six, but the six is one less than.

So we've already got to have moved a bead away.

So let's have a look at the beads and see what happens.

Six is one less than seven.

Let's look at that again.

There's our seven.

One less than seven is six.

Six is one less than seven.

And let's look at the last one.

Hmm is one less than eight.

So what number is one less than eight? I've got my eight beads there.

I want to know what is one less than that.

What number is one less? So let's move one of those beads.

So we've moved a bead across and we can see that seven is one less than eight.

Well done.

Your turn to have some practise.

So you're going to need some number cards.

The number cards, one, two, three, four, five, six, seven, eight, and nine.

And you're going to turn them all over so you can't see the numbers, and then you're going to choose one and turn it over.

So Jun's had a go and he turned over the number four and his job is to work out what number is one less than four.

So he's going to find one less than four.

So he got out his four beads or four counters in this case, and he moved one of them away, and he worked out that one less than four is three.

So use your cards and use your counters, or cubes, or beads, or even cars maybe, whatever you've got around you to have a go at Jun's activity.

Turning over a card and finding the number that is one less than the number on your card.

So pause the video and we'll have a look at some possible cards that you might have turned over in a minute.

I wonder if you picked any of these cards.

I picked the card number five first.

So I got out five counters and then I moved one of them.

You can see I moved one of them away and I had four counters, so I know that one less than five is four.

Then I picked card six.

So I put out my six counters, but I needed to find one less than six.

So I moved one counter away and I saw that one less than six is five.

And then I got the card number seven.

So I got my seven counters, but I knew I had to find one less than seven, so I moved one of my counters away and I could see that one less than seven was six.

I wonder if you picked any of those cards.

Right, well, in the first part of our lesson, we've been finding one less by using objects using manipulatives, but in this second part of our lesson we're going to find one less by counting.

We had a little look at the number track, didn't we? We're gonna really explore how we can use counting to find one less.

So let's have a look.

Here are our cars again, and we knew that when we had four cars and one of them drove away, we knew that one less than four was three.

And there goes our car.

One less than four is three.

And when we count, we know that three is the number before four when we count.

There's our key words, the number before.

So if we count, three is the number before four.

Sophia's here to help us count backwards to find that number before four in the count.

So let's count backwards and have a look at the number track as we go.

Are you ready to count? 10, nine, eight, seven, six, five, four, three.

Three is the number before four, and we know that one less than four is three.

It's that number before in our counting.

Let's have a look at counting with our beads.

Remember we looked at this one in the first part of the lesson.

We used our beads to find one less than five.

Now let's just think.

What's the number before five in our counting? We're going to count backwards this time because we're going to find one less.

So what's the number before five? So let's see if we can count.

And Sophia's here to help us count backwards.

Keep your eye on the beads as well.

Are you ready? 10, nine, eight, seven, six, five, four.

So you can see on the number track, four is the number before five when we count.

So one less than five is four.

So what's the number that is one less than eight? You see we've got our eight beads there, but we're going to think about counting.

So what's the number before eight when we count? Let's have a look.

Sophia's ready to help us count backwards from 10 again to find the number before eight.

Are you ready? 10, nine, eight, seven.

So on our number track, we can see that seven is the number before eight.

So we can say that seven is the number before eight when we count, and one less than eight is seven.

Sophia's found another way to say it.

She said one less than eight is seven.

She can also say that seven is one less than eight.

So let's see if we can find those two ways of saying things as we move on to the rest of our lesson.

Okay, one for us to do together and then one for you to do on your own.

So let's have a look at the left hand side.

One less than two is hmm.

So can we use our counting? We've got no beads or counters to help us this time.

We're going to use our counting.

Can we use the number track to count backwards to find one less than two? Let's have a go.

Two, one.

Did you count all the way back from 10 or can we just count from two? So the number before two is one.

One is one less than two.

So there's two ways that Sophia said it, we can say as well.

So your challenge is to have a go and find out what one less than nine is using the number track.

So pause the video and have a go.

How did you get on? Did you count from 10 or did you just count from nine to find the number before eight? Yes, we could say 10, nine, eight, or we could just have started at nine and said nine, eight, but eight is the number before nine.

So one less than nine is eight or eight is one less than nine.

Sophia's had a go.

Now, is she correct? Sophia says I can count and say the number before seven, one less than seven is eight.

Is Sophia correct? Pause the video and have a think.

Jun says that Sophia is not correct.

Jun says the number before seven is six.

One less than seven is six.

Shall we count with Jun to find out? Are you ready? Seven, six.

June only started at seven didn't he? So the number before seven is six.

One less than seven is six.

Time for you to have some practise.

Again, we've got our cards.

So you're going to turn over a card 'cause you're gonna put them out so you can't see the numbers.

Turn over a card and see if you can use counting to find one less than the number on your card.

And we've got those two sentences that Sophia showed us earlier, haven't we? One less than hmm is hmm, or hmm is one less than hmm.

So can you complete those sentences? and Jun's reminding you that you might want to use the number track to help you.

So pause the video and then we'll come back together and see which numbers we chose.

I wonder if you picked any of these cards.

I picked the number one.

So what's one less than one? So what's the number before one? If we count down, let's count down from 10.

10, nine, eight, seven, six, five, four, three, two, one, zero.

Oh, so one less than one is zero or zero is one less than one.

That was an interesting one to pick, wasn't it? I also picked the number five.

So can we use the number before five to help us to find out what is one less than five? Should we count from 10 again? Are you ready? 10, nine, eight, seven, six, five, four.

The number before five is four.

So one less than five is four or we can say four is one less than five.

And finally, I turned over the number eight.

Can you count backwards with me from 10 to find the number before eight? Are you ready? 10, nine, eight, seven.

Seven is the number before eight.

One less than eight is seven, or seven is one less than eight.

I wonder if you picked any of those cards.

Well, fantastic learning you've been doing today, learning all about finding one less than a number or one fewer, and then thinking about counting and the number before.

So now we come to the end of our lesson.

You can use manipulatives like toy cars or beads to find one less than a number.

And you know that when you count, the number before is one less than the number you last said.

And a number track can help you to find one less than a number and it can help you to find the number before.

Thank you for your hard work today and I hope I'll see you again.