Lesson video

Hello, my name's Mrs. Cornwell and I'm really pleased to be working with you today.

We're going to use some of the things you already know to help you with some new learning and I know you're going to do really well, so let's go.

Today's lesson is called order and Compare decade numbers on number tracks and it comes from the unit, counting in tens, decade numbers.

So by the end of today's lesson, you should be able to order those decade numbers from 0 to 100 on a number track and say which number is greater than or less than another number, another decade number.

So the words that are going to be important today, we've got greater than and we've got less than.

So the first part of today's lesson, you will order decade numbers on a number track and then you'll move on to comparing them in the second part of the lesson.

In this lesson you will meet Alex and you will also meet Izzy.

Alex has some cards with the decade numbers on them, but he drops them.

Can you help him to put the numbers back in the correct order? "I wonder what I could do to help myself," says Alex.

So he spreads his cards out so that they look like this.

And you can see he's got a number track below, in the right order in the correct order, hasn't he? What do you think he could do to help to put them in order? That's right, he matches each card to the number track.

10, 20, 30, 40, 50, 60, 70, 80, 90, 100.

Alex's teacher gives him an empty number track.

How will he order his numbers now? The numbers aren't on that number track at the bottom are they? What will he do to order his numbers now? So Alex counts in tens and looks for each number as he counts.

Which number do you think he should look for first? So zero's not on the number track is it? So which number should he look for first? That's right, he would look for number 10, wouldn't he? So, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100.

Excellent.

Izzy has a different idea so she wants to order them, but she has a different way of doing it.

She says, "I've spotted a pattern that can help us." Can you see a pattern there? That's right, so if you look at the decade numbers, they all have a 1, 2, 3, 4, 5, 6, 7, 8, 9 pattern when they're spread out like that, don't they? And we know that the digit there, the numeral, represents a number of tens in that number.

So you can think about the groups of 10 to help you order the number, can't you? The number before zero in a decade number tells you how many tens are in it.

So we can use that to help us.

So which number should you look for first? There are the cards and they're all muddled up again, aren't they? Which number will we look for first? Oh, so we've got, haven't got a zero card, have we? That's not on the number track, so we know that's no tens.

But then we're going to look for the number that has one ten.

That's right, so there's ten, one ten.

Then what will we look for? So we've got zero tens, one ten.

Which number do you think we'll have two tens? That's right, it's 20, isn't it.

Then which number will have three tens.

Excellent, so we've got zero tens, one ten, two ten, three tens.

What do you think will be next? That's right, it will be four tens, 40, then it will be five tens, then it will be six tens, then seven tens, then eight tens, then nine tens.

And then last of all we know 100 has ten tens, excellent.

So that was a different way to order the numbers, wasn't it? Now it's your turn to have a try.

So spread out your decade number cards on the table and put them in order by counting in tens.

So like Alex did, you can count in your decade numbers to help you order them.

Well done, excellent.

Alex and Izzy take some of the cards each to order.

Here are Alex's cards.

So he is got 20, 50, 40 and 30, and you can see there's an empty number track below as well, isn't there? Alex says, "I can't put them on the number track because I don't have all of the numbers." Do you think he can put them in order because he hasn't got all of the numbers from the number track there, has he? Oh, Izzy's saying, "I think I have an idea." So there are the numbers to order.

Izzy says, "Perhaps I can count in tens along the number track to help me." So she's using the method that Alex used before, isn't she? 10, 20, 30, 40, 50, 60, 70, 80, 90, 100.

Did you notice how she kept counting to check she was right? Well done, excellent.

Alex is going to use a different method now, he's saying, "I can look at the number of tens in each number," and if you look at that you can see 20 has two tens and then we've got three tens, four tens, five tens, haven't we? So you can also use that strategy, that method.

So your turn again now, here are Izzy's cards, where would they go on the number track? So we've got 80, 60, 70 and 90.

Remember to look at the number of tens in each number to help you.

And you could also count in tens like Izzy did to check that you were right, couldn't you? So have a try at that and then we'll have a look together.

Okay, let's see how we got on then.

So, what method did you use, how did you do it? You can count along the number track to find the correct position.

You can count using your decade numbers, count in tens, can't you? So you might have used that strategy, that method.

10, 20, 30, 40, 50, 60 comes next, doesn't it, 70, 80, 90, and then keep counting to check that it still fits, 100, yes.

So you've got to the end of the number track with 100, you know you are right.

You could also look at the number of tens to help find the correct position.

So you could use that to check if you wanted, couldn't you? So there we've got 60, which we know is six tens, and then after six comes seven.

So after six tens comes seven tens, after seven comes eight.

So after seven tens comes eight tens, and after eight tens it will be nine tens.

That's right, well done.

I want to place these numbers on my number track.

So we've got 70, 100 and 30.

"These are more tricky," says Izzy, "they do not follow on from each other when I count." So the other numbers, once you've got the first one, you could keep counting because they all followed on from each other when you count in tens.

But these ones are a bit different aren't they? But you can look at the number of tens to help you or you can count in tens along the number track, so you can use exactly the same methods, exactly the same strategies to help you.

So let's have a look.

Which one would you place first on a number track do you see there out of the numbers? So we haven't got a 10 there, have we? We've got 70, 100 or 30, but which one do you think would come first on the number track when you count along? That's right, it will be 30 won't it? You go 10, 20 and then you come to the 30 first.

Which one will come next, I wonder? That's right, it will be 70 won't it? And then which one will come last, it will be 100.

And you could check using the number of tens couldn't you? You could think, well, three tens must be lower than seven tens.

Okay, because three is lower than seven, and then so it would go three tens, seven tens and then ten tens wouldn't it? Well done.

Alex puts two different number cards on the number track like this.

So he puts on 40 and 80.

He says, "I can find the other numbers by counting on from the start of the number track." 10, 20, 30, and then we can see 40 is there, 50, 60, 70, 80, 90, 100.

Izzy says, "I wonder if I can use the numbers I already have to help me do this." So I wonder if we, instead of starting right from the start of the number track, we could start with 40.

So there we can see 40 and 80, can't we? And we've got Izzy here, and she says, "I can count from different starting points.

I will use the numbers I have." So she knows how to count on from 40, doesn't she, and how to count back from 40? So she'll use those instead of always having to start from the start of the number track, I can start from 40 and count on.

So she's got 40, 50, 60, 70 and then you can see that you're right because then that gets you to 80 when you're counting in tens, 80 is the next number after 70.

Okay, then she says, "I can start from 40 and count back," 40, 30, 20, 10.

Then she says, "I can start from 80 and count on," 80, 90, 100.

So now she's found all of those numbers.

She could count back from 80 as well, couldn't she? But she already found those numbers by counting on from 40.

So she's found all of the numbers on the track.

Now it's your turn again.

So use the numbers on the track to find the decade numbers that are between 30 and 70 so the numbers that are after 30 when you count in tens but before 70, and think about how you can check you're right.

So I'll give you a bit of time to do that now.

Okay, let's see how we got on.

So you can start from 30 and count on, can't you? You could say 30, 40, 50, 60.

What else could you do to find them? Is there a different way? That's right, you can start from 70 and count back, can't you? 70, 60, 50, 40, that's right.

And then you can check you're right, can't you, because you can check by counting from the start of the number track in tens, couldn't you? Or you could count back from the end of the number track and check that you had all of the numbers, but you knew you had all the numbers between 30 and 70 so you knew you were right, well done.

Alex has found some number tracks that have some pieces missing.

Help him to replace the missing decade numbers.

So we've got just part of a number track there, but we can see the number 70, can't we on it? So what will we do to find the missing numbers do you think? That's right, well you could think about the number of tens and think 70 has seven tens.

So after it, it would have to be the number that has eight tens, or you could think, I'm going to use my counting in tens strategy and I'm going to do 70 and then count on to 80, and then counting backwards, you could think I've got seven tens there.

So if I think about the number that will come before it when counting in tens, it will be the number with six tens, won't it, 60, or the number with five tens.

But you could also think, I'm going to count back and go, say, 70, 60, 50.

And then here's another one.

So 30, so you can think, what's the number after 30 going to be? If you're counting in tens, 30, that's right, it will be 40, and you can check it by saying there's three tens and next comes four tens.

And then the number before 30, so you can count backwards, can't you, and say 30.

So then it would be 20, and you can check it and think, well I've got three tens, and then if I go to the decade number before that it's going to be two tens.

And then we've got a number track with 100 at the end here.

And so you could say, have a think that's right.

You could say 100, I'm going to count backwards and say 90, 80.

Or you might think I know 100 is ten tens, so then it must be nine tens, eight tens, well done.

So now your turn again, fill in the missing decade numbers on the number track.

So you've seen some different strategies you can use.

You can count in tens or you can think about the number of tens.

So you can use that to help you find the missing numbers on here, can't you? So I'll give you a bit of time to think about that.

Okay, so how did you do? So 50, the number after 50 would be 60, and five tens after that would be six tens, that's right.

And then going backwards, so you'd say 50, 40, 30, or five tens, four tens three tens.

Here's another one for you to look at then.

Okay, so how did we get on? So we've got 60 there, haven't we? If we count on from 60, we will get 70, or you might have looked at the number tens and thought six tens, seven tens, and if you count back from 60, you will get 50, that's right.

And you can go from six tens to five tens.

Okay, and then one more here.

So have a think about that one.

Okay, so you can see you've got 90 at the end of the number track.

So if you count backwards from 90, you'll go 90, 80, 70, and you can check it and say nine tens, eight tens, seven tens, can't you, well done.

So here's your task for this first part of the lesson then.

So here are some parts of empty number tracks.

So use your decade numbers and the empty number track to help you fill in the missing numbers.

So you can see you've got 20 and you've got to think about what the missing numbers when counting in tens will be there.

And then you've got 50 on the second one.

So think about what strategy you would use there.

And then you've got some other ones there, one with 90 and 70 and 40.

So pause the video now while you have a try at that.

So how did we get on then, let's have a look.

So that first number track has 20 at the beginning.

So you can count on from 20, can't you? You can say 20, 30, 40, 50, or you could think two tens, three tens, four tens, five tens, and then that next number track has 50, and you can count backwards, can't you, and say 50, 40, 30.

Or you could say five tens, four tens, three ten, and then you've got 90 in the middle.

So if you count on from 90, you go 90, 100 don't you? And then before 90, if you're counting backwards, you would say 90, 80, and you can check I've got eight tens, nine tens, ten tens there, haven't I? Okay, and then we've got 70 here, haven't we? So we could say count on from 70, we go 70, 80 or seven tens, eight tens, and counting back from 70, 70, 60, 50, seven tens, six tens, five tens.

And then this bottom one here, 40, if you count on from 40 you will get 50, four tens goes to five tens when you count in tens, doesn't it? And the number before 40, you would say 40, 30, that's right, or four tens, three tens.

Excellent, well done, you've worked really hard in this first part of the lesson.

So the next part of the lesson is to compare decade numbers using them, the words greater than and less than.

So you can compare decade numbers using greater than and less than.

So we've got 10 here, haven't we? And we've got 100 there.

When one number represents a larger amount, you say it is greater than the other number.

So which number there do you think is greater than the other? That's right, so 100 is greater than 10, isn't it? It's got a larger amount, there's more of them.

So look at the number track.

What do you notice about the position of the number that is greater than the other number? That's right, it comes at the end of the number track, doesn't it? It's much further along, because if you were counting, you would get to that number later, wouldn't you? When one number represents a smaller amount, you say it is less than the other number.

So we can see there that 10 has a smaller amount.

So 10 is less than 100, and there it is on a number track.

What do you notice about the position of the number that is less than the other on the number track? That's right, it comes earlier doesn't it? It's near the beginning of the number track because you say it's sooner when you are counting.

So use the stem sentences to compare these numbers.

So mm is greater than mm, mm is less than mm.

So if you look at those numbers, what can we use to help us? That's right, you could think about the amount in each number, couldn't you? You can think about 70 has a greater amount, doesn't it, than 30.

So we can say 70 is greater than 30, can't we? And we can also see that it has more tens, doesn't it? Seven is more than three.

And you could also think it comes later, further along, nearer the end of the number track, doesn't it? Okay, let's think about which number is less than.

So if we see 30, we look at 30, we can see it has a smaller amount, doesn't it? So we can say 30 is less than 70 and we can also think it has three tens, which is less than seven tens, or you could think it comes near the beginning of the number track.

You say it's sooner when you count, don't you? Izzy looks at these two decade numbers.

How can she find which number is greater? So we've got 50 and we've got 80.

So what could she do to find out which is a greater number? So Alex says, "You could think about how many groups of ten are in each number," and Izzy says, "I could imagine the numbers on a number track." So there's 50 and there's 80, the five represents five tens.

So we are thinking about the number of tens in the number, and the eight represent eight tens.

You know that eight is greater than five, so eight tens is greater than five tens.

And you know that five is less than eight, so five tens is less than eight tens.

And there are the numbers on a number track there.

And you can say 80 is greater than 50 because eight tens is greater than five tens, 50 is less than 80, because five tens is less than eight tens.

So let's compare the numbers below then, we've got 20 and we've got 90, haven't we? So if we have a look, nine is greater than two.

So we're looking at the number of tens in each number, nine represents nine tens in 90 and the two represents two tens in 20.

So, nine is greater than two.

So nine tens is greater than two tens.

Therefore 90 must be greater than 20.

And then two is less than nine, so two tens is less than nine tens, so 20 is less than 90.

So you are using what you already know about two and nine to help you work out how to compare these decade numbers.

And if you look at them on the number track there, you can see that the 20 is near the beginning because you say it earlier when you count, so it's less and the greater number, 90, is nearer the end of the number track, 'cause you say it later when you count.

So now it's your turn.

Compare the two numbers and complete the stem sentences and you've got 60 and 30.

So you're going to be saying mm is greater than mm, so mm tens is greater than mm tens, and then you'll say mm is less than mm, so tens is less than mm tens, okay? So pause the video now while you have a try.

Okay, so how did you get on? So if you look at 60, we know that the six represents six tens and that can help us, can't it? So we could compare the six in 60 to the three in 30, can't we, 'cause we know the three represents three tens in 30.

So we can say six is greater than three.

So six tens is greater than three tens.

And then we can also look at which number is less.

We can say three is less than six.

So three tens is less than six tens.

And from that we can work out which is greater, which is the greater number, which is greater than the other, and which is less.

So we can say that 60 is greater than 30, 30 is less than 60.

So you can also compare three numbers instead of two numbers, can't you? Let's have a look at the numbers we've got here.

We've got 70, 100 and 30.

We need to think about which number represents the largest amount.

What could you use to help you? That's right, so you can see that 100 has ten tens in it, doesn't it, the 10 represents 10 tens.

That must be greater than 70 and also greater than 30.

So 100 is greater than 30, 100 is also greater than 70.

Now let's have a look at which number represents a smallest amount.

Okay, so we can see there can't we? When we look at the number of tens in each number, 30 has three tens and we know that three is less than seven, and so 30 must be less than 70.

And we also know three is less than 10, so 30 must be less than 100.

And we can see it here, 30 is less than 100, and 30 is also less than 70.

Now it's your turn again.

So you are going to compare the numbers on the number track and complete the stem sentence.

You're going to say 70 is greater than, and 70 is less than, so you can compare 70 to both of the other numbers on the track there, can't you? So have a think about this.

And Izzy's put, "I wonder if you could complete these sentences using some of the missing decade numbers." We can't see all of the numbers on the number track, but you could try and imagine them like Izzy said she was going to do earlier, couldn't you, and so you may also be able to complete these stem sentences using numbers that we can't actually see on the number track at the moment.

So pause the video and have a try.

Let's see how we got on there then.

Comparing 70 to the other numbers on the number track, you could say 70 is greater than 30, couldn't you? Because seven tens is greater than three tens, seven is greater than three.

You could also have imagined some of the other numbers that were on there.

And you might have said 70 is greater than 40 or 50 or 60, because those are the numbers that you would get to if you count on, 70, 30, 40, 50, 60 and then 70.

And also you might have thought of the numbers that come before 30 on the number track.

So you might have said that 70 is greater than 10 and it's also greater than 20.

Okay, what about what 70 is less than then? Comparing it to the other numbers on the number track, you could say that 70 is less than 100, couldn't you? Because seven is less than 10, so seven tens must be less than ten tens.

But you might have also thought of those other numbers, okay? And you might have thought 70 is also less than 90, 'cause you know that would be further along the number line than 70, and 70 is less than 80.

So you may have imagined those numbers as well.

Well done with that.

Now look at this number track here and we can see the decade numbers again.

Find two numbers that are greater than 80.

You go mm and mm are greater than 80, what could it be? That's right, and then you can say 90 and 100 are greater than 80, aren't they? They come further along the number line, nearer the end of the number line.

And also we know that nine tens is greater than eight tens and 10 tens is greater than eight tens.

You could also say look at the less than 30 for example.

So find two numbers that are less than 30, mm and mm are less than 30.

That's right, so if you have a look at the numbers that come near the beginning of the number track than 30, you can see that you could have had 10 and 20 are less than 30.

And you also could use the number of tens to check that you were right.

You could think, well 30 has three tens, but two tens is less than three tens, so 20 must be less than 30, and one ten is less than three tens, so 10 must be less than 30, well done.

So now it's your turn again, okay, look at the number track and find all the decade numbers that are greater than 40.

And you can also use the position on the number track to help you check that you are right.

Okay, so what did we say? We could have said 50 is greater than 40, okay, 'cause we know that five tens is greater than four tens.

60 is greater than 40, six tens is greater than four tens, 70 is greater than 40, seven tens is greater than four tens.

80 is also greater than 40.

90 is greater than 40, and 100 is greater than 40.

And you can see that all of those numbers come further along the number line after 40, don't they? So we know that they are greater.

Okay, now let's think about all the decade numbers that are less than 40.

I'll give you some thinking time to do that.

Okay, so let's have a look then.

So there's 40, we know that's four tens.

We could have 10 is less than 40 'cause one ten is less than four tens, isn't it? 20 is less than 40, two tens is less than four tens, and 30 is less than 40, three tens is less than four tens.

And if you look at the position on the number track there, they come near the beginning of the number track.

You say them earlier when you count, don't you, so that's another way to check that we are right.

So now your task for this second part of the lesson is to look at the number track and try to imagine the missing numbers.

Imagine all the decade numbers that are greater than 20 and less than 90.

Use your stem sentences to describe your thinking.

So you'll say mm is greater than 20, mm is less than 90.

Then use your decade card, your decade cards, and an empty number track to check if you are right.

Okay, so pause the video while you have a try at that.

Okay, so how did we get on with that then? So let's look at these stem sentences.

We need the same number that is greater than 20 and also less than 90.

So let's have a think of what could be there.

We could have 30, couldn't we because we can see 30 is greater than 20, 30 is less than 90, it comes in-between those two numbers.

And you could use the number of tens in the number to check, couldn't you? We could also have 40 is greater than 20 and 40 is less than 90.

And again, we could use our tens to check, but you could also say it, see that it's in-between those two numbers, 20 and 90.

We could have 50, that's right, 50 is greater than 20, 50 is less than 90, 60 is greater than 20, 60 is less than 90, 70 is greater than 20, 70 is less than 90, and 80 is greater than 20, and 80 is less than 90.

So you could use those tens in the numbers to check whether it's greater than or less than 20, greater than 20 and less than 90 as well.

And then the positions on the number track just show us, let us check, don't they that the numbers are between 20 and 90.

So well done, you've worked really hard in today's lesson.

You've done a really good job.

So let's think about what we've learned today when we've been ordering and comparing decade numbers on a number track.

So we found out that decade numbers can be ordered on a number track by counting in tens, or by looking at the number of tens in the number.

You can also compare decade numbers using greater than and less than, can't you? So well done, you've used lots of your learning that you already had to help you with some new learning, which is excellent, isn't it? So I've really enjoyed today's lesson and working with you.

Well done.