Lesson video

Hello, my name's Mrs. Cornwell and I'm going to be helping you with your learning today.

Now, today we're going to be finding out all about two-digit numbers.

We're going to be looking very carefully thinking about what we notice, looking for any patterns that can help us so we can use things that we already know to help us with new learning.

So I'm really looking forward to working with you today.

I know you're going to work really hard and will do really well.

So let's get started.

Our lesson today is called Explore the counting sequence for counting to 100 and beyond, and it comes from the unit Counting and representing the numbers 20 to 99.

So in our lesson today, we're going to explore that counting sequence and we're going to look for the patterns within it that can help us to remember the order of the numbers and to help us to cross that tricky tens boundary.

Okay, so by the end of our lesson today, you should feel much more confident with counting forwards and backwards up to 100 and beyond.

So our keywords for today are decade my turn, decade your turn, and digit my turn, digit, your turn, and dual counting, my turn, dual counting, your turn.

Well done, excellent.

So, the first part of our lesson is about counting forwards to 100 and beyond.

And in this lesson you will meet Andeep and you'll also meet Laura.

And here they are, look.

So the children are seeing how long it takes them to tidy up.

Andeep tidies the Lego.

It's in a bit of a mess, isn't it? "While you tidy, I will count to see what number I reach by the time you finish," says, Laura.

"You tidied the bricks by the time I counted to 67," she says.

Then Laura tidies the pencils.

"Now, I will count while you tidy," says Andeep.

"You tidied the pencils by the time I counted to 46." Perhaps you could try this with a friend.

You may be able to predict what number you think you will reach.

And so here are Andeep and Laura with some of their friends.

The children play a game.

One child picks a number card and they count forwards from that number.

When they reach the next multiple of 10, they all say it together, 86.

So they're going to count on from 86, 87, 88, 89, 90.

That's the next multiple of 10, isn't it? 91, 92, 93.

Perhaps you could try this with your friends.

There are patterns on a 100 square that can help us count from one to 100.

Let's look at some of those patterns.

We can split the 100 square into different decades, can't we? There's the ones, the teens, the twenties, the thirties, the forties, the fifties, the sixties, the seventies.

I wonder what's coming next? That's right, the eighties and the nineties.

Well done.

So when we count the pattern within each decade helps us.

"The tens digit at the start of each number tells us which decade a number is from," says Laura.

The tens digit here in this row is four for most of the row, isn't it? "This must be the forties decade." So all of the numbers with a tens digit of four are the forties decade.

"The ones digit follows the pattern, one, two, three, four, five, six, seven, eight, nine.

Then the tens digit changes." The next multiple of 10 comes at the end of the row and the 10 digit changes.

And it moves to 50 at the end of the forties, doesn't it? That means the fifties decade will be the next row.

And there it is.

Use the patterns in the 100 square to count up to 100, pointing to each number as you count.

Okay, so let's try that.

One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100.

Well done, excellent.

Did you remember to point to each number as you counted? Well done.

We can count two-digit numbers in two ways.

This is called dual counting.

So for example, you can say 45, 46, 47, 48, 49 50.

Or you can say four tens five, four tens six, four tens seven, four tens eight, four tens nine, five tens.

Well done.

So now it's time to check your understanding.

Dual count forwards from 75 until you reach 80, okay? So dual count means you will count the numbers in two ways.

So pause the video now while you try that.

Okay, and let's see how you did.

75, 76, 77, 78, 79, 80.

And then the other way to count was seven tens five, seven tens six, seven tens seven, seven tens eight, seven tens nine, eight tens.

Well done if you did that.

We can also dual count on a Gattegno chart.

And here we have one here.

Let's count forwards from 83 to 90, tapping the numbers as we say them.

83, 84, 85, 86, 87, 88, 89, 90.

Okay, and now let's count them the other way.

Eight tens three, eight tens four, eight tens five, eight tens six, eight tens seven, eight tens eight, eight tens nine, nine tens.

Well done.

So now it's time to check your understanding again.

Dual count forwards from 63 to 70, tapping the numbers as you say them, okay? So pause the video now.

Remember you are counting the numbers from 63 to 70 in two ways.

So, pause the video while you try that.

Okay, and let's see how you got on.

63, 64, 65, 66, 67, 68, 69, 70.

And then we would say six tens three, six tens four, six tens five, six tens six, six tens seven, six tens eight, six tens nine, seven tens.

Well done if you did that.

Okay, so here are the children and they've got a row from the 100 square.

It's a nineties, isn't it? Let's look at the nineties row.

100 is the next multiple of 10.

Can we keep counting past 100? So there's 100, and Laura says, "The last number on the 100 square is 100." We must always stop counting at 100.

Hmm, do you think she's right? But then Andeep says, "I know there are numbers greater than 100.

We can keep counting." So let's see how we do that.

So we count all of the numbers up to 100, and then when we reach 100, the pattern repeats.

So let's take a look.

101, 102, 103, 104.

And so on.

Each time we say 100 and the next number.

With some, so perhaps you could practise that with some friends.

You could use a Gattegno chart or perhaps two 100 squares.

Okay, so now it's time to check your understanding.

Use a Gattegno chart to count from 93 to 102, okay? So pause the video now while you try that.

Okay, and let's see how you got on.

93, 94, 95, 96, 97, 98, 99, 100, 101, 102.

Excellent, well done.

So here's a task for the first part of the lesson.

You will need some two-digit number cards and then sit in a circle with some friends or perhaps just a partner and pick a number card.

Okay, so the children here have picked 95.

Count forward from that number with each child taking a turn.

And when you reach the next multiple of 10, say it all together.

When you've counted round the circle twice, stop.

And then the next child can pick a card, okay? So pause the video now while you practise that.

Okay, and let's have a look then.

You may have done this.

So you could have picked the number 96, for example.

97, 98, 99.

What's the next multiple of 10? That's right, 100.

So they all say it together.

101, 102, 103.

So well done if you did that.

So now let's have a look at the second part of our lesson where we practise counting backwards.

Laura says she will count back from 84 to see if Andeep can run around the field before she reaches zero.

Perhaps you could try this with some friends.

Pick an activity and ask a friend to count down from a certain number.

Try to complete the activity before your friend reaches zero, and then perhaps you could try some different activities as well.

Okay, so we know the patterns in the 100 square can help us to count forwards to 100.

Let's use the patterns to help us count back from 100 pointing to each number as you count.

Are you ready? Count with me.

100, 99, 98, 97, 96, 95, 94, 93, 92, 91, 90.

Well done, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, nine, eight, seven, six, five, four, three, two, one.

Well done, excellent.

Did you use those decades to help you think of the number before the multiple of 10? Well done if you did.

So it can be tricky to count back from a multiple of 10.

Let's use dual counting to help us count back from 70 to 65.

Are you ready? "I know the decade before the seventies is the sixties," says Andeep.

"So when I count back from 70, each number will have six tens." Are you ready? 70, 69, 68, 67, 66, 65.

Well done.

And now let's count the other way.

So seven tens, six tens nine, six tens eight, six tens seven, six tens six, six tens five.

Well done, excellent.

So now it's time to check your understanding of that.

Use dual counting to help us count back from 90 to 85, okay? So pause the video now while you try that.

Okay, and let's see how you got on.

So Andeep saying, "I know the decade before the nineties is the eighties, so when I come back from 90, each number will have eight tens." 90, 89, 88, 87, 86, 85 or the other way, nine tens, eight tens nine, eight tens eight, eight tens seven, eight tens six, eight tens five.

Well done if you did that.

We know we can dual count on a Gattegno chart as well, can't we? So let's practise.

Let's count backwards from 60 to the previous multiple of 10.

Tapping the numbers as we say them.

Are you ready? 60, oh what decade is before the sixties? That's right.

So we know it's the fifties, so it will be 59, 58, 57, 56, 55, 54, 53, 52, 51 50.

Well done.

So now let's count the other way.

Six tens, five tens nine, five tens eight, five tens seven, five tens six, five tens five, five tens four, five tens three, five tens two, five tens one, five tens.

Well done.

So let's check your understanding of that now.

Dual count backwards from 90 to the previous multiple of 10.

Okay, so pause the video while you practise counting in those two different ways.

So let's see how you got on 90.

Did you think of the decade before the nineties? That's right.

89, 88, 87, 86, 85, 84, 83, 82, 81, 80.

Well done.

And now the other way.

Nine tens, eight tens nine, eight tens eight, eight tens seven, eight tens six, eight tens five, eight tens four, eight tens three, eight tens two, eight tens one, eight tens.

Well done if you did that.

So here are the children, and they're playing a game again.

One child picks a number card and they count backwards this time from that number.

When they reach the previous multiple of 10, they say it together.

So they've picked 84.

So let's see what they do.

83, 82, 81, 80, that's right.

79, 78, 77.

And then they would pick a different number card, wouldn't they? And practise it again.

Okay, so here's the task for the second part of our lesson today.

You will need some two-digit number cards, and then you need to sit in a circle with a friend or group of friends and pick one of the number cards.

So they pick 34, count backwards from that number with each child taking a turn.

When you reach the next multiple of 10, say it aloud.

When you've counted round the circle twice, stop.

And the next child can pick a card.

So pause the video now while you try that.

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

You may have done this.

So you may have picked, for example, 34 and gone 33, 32, 31, 30, 29, 28, 27.

So well done.

You've worked really hard in our lesson today, and hopefully you are now feeling much more confident about counting forwards and backwards within 100 and beyond 100.

So well done.

So let's have a look at what we've learned in today's lesson then.

There is a set counting sequence for counting to 100 and beyond.

The patterns in the numbers make counting to 100 and beyond easier.

The tens digit in a two-digit number indicates which decade it belongs to.

The ones digit in a two-digit number follows the pattern one, two, three, four, five, six, seven, eight, nine, and we can count in two ways.

This is called dual counting.

So well done.

You've worked really hard today, and I've really enjoyed our lesson.