Lesson video

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

I'm really looking forward to today's lesson.

I know you're going to work really hard and we'll do really well, so let's get started.

Welcome to today's lesson, which is called Create Addition and Subtraction Stories and it comes from the unit Additive structures, addition and subtraction.

So in our lesson today, we're going to learn to tell our own addition and subtraction stories and write equations to match.

So by the end of the lesson, you should feel much more confident with doing that.

So the words that are going to be important for our learning today, our key words are add, my turn, add, your turn, and increase, my turn, increase, your turn and subtract, my turn, subtract, your turn and decrease, my turn, decrease, your turn.

Excellent.

Well done.

So the first part of our lesson today is when we're going to find out how to tell addition stories and write equations to match.

In our lesson today, you'll meet Aisha and also Alex.

So Aisha is playing with the toy cars.

She wants to tell a first, then, now story, an addition story.

Let's help her.

So she's wondering, "What number should I start with?" she says.

She decides to start with four cars.

First there were four cars in the car park And then Alex is there and he's reminding her, "Remember the first number must increase, because it's an addition story." Then two more cars parked in the car park and there they are.

Now there are six cars in the car park.

Let's use counters to represent Aisha's story on a first, then, now board and write the equation to match.

First there were four cars in the car park.

So we write four, don't we? Then two more cars parked in the car park, so four plus two.

Now there are six cars in the car park.

Four plus two is equal to six and there, we can see it underneath as well, can't we? Alex tells a story about the animals he's playing with.

Okay, so we can see some lions.

He must be playing with toy lions.

First there were four lions in the zoo.

Then two more lions came to the zoo.

Now there is six lions in the zoo.

Let's use counters to represent Alex's story on a first, then, now board and write the equation to match.

First there were four lions in the zoo.

So we write four, don't we? Then two more lions came to the zoo, so four plus two.

Now there are six lions in the zoo.

Four plus two is equal to six.

What do you notice about both the stories the children told? What's the same about them both? If we use the same number at the start of the story and the same number is added, then the number at the end of the story will also be the same.

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

Okay, so use your own objects to tell a first, then, now addition story and use the same numbers that Alex and Aisha used, okay.

So perhaps you could use some toys or some counters or something that you have around you, okay? And there's some stem sentences to help you here.

First there were four mm, then two more, mm, now there are six mm.

Okay, so pause the video now while you try that.

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

Okay, so I think I'm going to tell my story.

I think I'm going to use, ooh, I think I'll use toy chickens in a farm yard.

So first there were four chickens in the farm yard, then two more chickens came into the farm yard, now there are six chickens in the farm yard.

So well done if you did that.

If we use the same number at the start of the story and the same number is added, the number at the end will also be the same.

Okay, so here's the second part of your check.

Which equation will represent this story? Okay, so we've got three options.

We've got A, B, and C.

A is six plus two is equal to four.

B is six, minus four is equal to two, and C is four plus two is equal to six, okay, so pause the video now while you have a think about that.

Okay, and what did you think? That's right.

Four plus two is equal to six, isn't it? Because there were four chickens at the start of the story and then we added two, four plus two to reach six at the end of the story.

So well done if you did that.

Aisha and Alex are making up addition stories using their teddies, both of their stories begin with seven.

okay? And there's Aisha and she's saying, "I think that both of our stories will end with the same number" and Alex is saying, "I think our stories could and with different numbers." Who is right, do we think? Let's have a look and see.

So we'll find out.

Here's Aisha's story.

First there were seven teddies on the mat.

Then two more Ted's got on the mat.

There they are.

Now there are nine teddies on the mat.

Seven plus two is equal to nine.

Here is Alex's story.

First there were seven teddies on the mat.

Then three more teddies got on the mat.

There they are.

Now there are 10 teddies on the mat.

Seven plus three is equal to 10.

So their stories ended with different numbers, didn't they? Why was that, do we think? Why do their stories end with different numbers? They each added a different amount to the number at the start of their story, didn't they? So you can see there, Aisha said seven plus two is equal to nine.

She added two teddies and Alex said seven plus three is equal to 10.

He added three teddies.

Could their stories have ended with the same number, do you think? That's right? If they had each added the same amount, then their stories would've ended with the same number, wouldn't they? Well done if you notice that.

So now it's time to check your understanding again, use your own objects to tell a story starting with seven, and then write the equation.

So pause the video now while you do that.

Okay, let's see how you got on.

So here, you may have said something along these lines.

First, there were seven pencils in the pot.

Then I put one more pencil in the pot.

Now there are eight pencils in the pot and your equation would've been seven plus one is equal to eight, that's right, well done.

Aisha makes up an addition story starting with five.

Alex thinks it will end with four.

Why can't he be right, I wonder? So let's have a look here.

First, there were five apples in the basket.

The counters are representing apples, aren't they? Then some more apples we're put in the basket.

So there's five there and some more are going to be added.

Now there must be more than five apples in the basket.

When you add to a group of objects, the number increases in size, the number at the end cannot be less than the number at the start of the story, can it? So well done.

So let's check your understanding again.

Aisha acts out an edition story that starts with six.

Which of these numbers cannot be at the end of her story? Okay? And explain why.

So pause the video now, okay, while you try that.

Okay, and what did we think? That's right.

It was five, wasn't it? Five cannot be at the end of her story because if you add to a group of objects, the amount at the end will not be less than the amount at the start.

Alex tells a first, then, now story, but the number at the start of the story does not change.

"It cannot be an addition story" says Aisha, "The number at the start did not increase." Is she right? What do we think? Oh, so there we can see there's this number at the start of the story, four plus zero is equal to four.

It was an addition story, Alex added zero, okay? So here is the task for the first part of today's lesson.

Alex is telling us what to do.

He's saying, "I will use my toys to tell my own first, then, now addition stories and Aisha's reminding us there, remember to write the equation to represent your story.

How many first, then, now stories can you tell that begin with the number five? And how will you know you've found all the possibilities? So pause the video now while you have a think about that.

So let's see how we got on.

You may have done this.

And there's Alex, he's saying, "I used toy cars.

First there were five cars in the garage." He's telling a story here, isn't he? There's his five cars.

"Then two more cars drove into the garage." There they are, "Now there are seven cars in the garage" and the equation that he would write to represent that is five plus two is equal to seven.

Well done.

Okay, so then we were asked how many stories we could tell that began with five, so let's have a look.

Okay, so five plus two is equal to seven is the first story Alex told and then we could have five plus three is equal to eight, five plus four is equal to nine, and five plus five is equal to 10 and you can work systematically in order, so you'll know you have found all the possible equations up to 10, can't you? So well done, you've worked really hard in the first part of our lesson today.

So the next part of our lesson is when we're going to look at telling subtraction stories and write equations to match those.

So here's Aisha again.

She's still playing with the toy cars and this time she wants to make up a first, then, now subtraction story, let's help her and she's saying, "What number should I start with?" First there were four cars in the car park and there they are.

"Remember the first number must decrease this time," says Alex, so it's a subtraction story, isn't it? He's reminding us.

So then two cars drove away and there they are driving off.

Now there are two cars in the car park.

So let's use counters to represent Aisha's story on a first, then, now board and write the equation to match.

So there we go.

First there were four cars weren't there, and then two cars drove away.

So four minus two and then we can see four minus two is equal to two, there were two cars left at the end of the story and there that's where we write it on our first, then, now board.

Alex tells a subtraction story about the animals he's playing with.

So he's got the lions again, hasn't he? First there were four lions in the zoo, then two lions left the zoo, now there are two lions in the zoo.

Let's represent Alex's story on a first, then, now board and write the equation to match.

Okay, so we're using counters to represent those lions again.

So first there were four lions in the zoo, and then two lions left the zoo, didn't they? So four minus two and then we can see there were two lions left in the zoo.

Four minus two is equal to two and there our equation is written underneath there as well, isn't it? What do you notice about both the stories the children told? Let's have a look at them both and compare them.

What do you notice that's the same? That's right.

If we use the same number at the start of the story and the same number is subtracted, the amount at the end will also be the same.

So now it's time to check your understanding again, use toys that you have and tell your own first, then, now story, a subtraction story this time using the same numbers that Aisha and Alex used, okay? And there's some stem sentences there to help you, the first, then, now.

Okay, so pause the video now while you try that.

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

Okay, so I think I'll picked a story about, oh chickens again.

First there were four chickens in the farm yard, then two chickens left the farm yard.

Now there are two chickens in the farm yard.

If we use the same number at the start of a story and the same number is subtracted, the number at the end will also be the same.

Okay, and then here's another check.

Which equation will match this story? It's a story we've just told and there's three equations there at the bottom.

So there's A, two plus two is equal to four, B, four minus two is equal to two, and C two minus two is equal to zero.

So pause the video now while you think about that.

Okay, and how did we get on with that? What did you think? That's right.

So it was B, four minus two is equal to two, is the equation to represent that story, isn't it? Aisha and Alex are telling subtraction stories using their teddies.

Both of their stories begin with seven.

Will their stories definitely end with the same number? What do we think? Let's have a look, let's find out.

Here is Aisha's story.

First there were seven teddies on the mat, then two teddies left the mat.

Now there are five teddies on the mat.

Seven minus two is equal to five and here is Alex's story.

First there were seven teddies on the mat, then three teddies left the mat, so now there are four teddies on the mat.

That's right and the equation to represent that is seven minus three is equal to four.

Why do their stories end with different numbers I wonder? They both subtracted a different amount from the number at the start of the story, didn't they? So now it's time to check your understanding again, use your own objects to tell a subtraction story starting with seven and then write the equation.

Okay, so pause the video now while you do that.

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

So here's my story.

First there was seven pencils in the pot.

Then I took one pencil from the pot.

Now there are six pencils in the pot.

There they are.

And my equation is seven minus one is equal to six.

So you may have done a story with those numbers or you may have had some different numbers, subtracted some different numbers in your story.

So well done.

So Alex makes up a subtraction story starting with five, and Aisha thinks it will end in seven.

Why can't she be right? So let's have a try.

We'll act out a story with counters.

First there were five and we'll say they're apples in the basket, they can represent apples.

Then some apples were taken from the basket.

It's a subtraction story.

So some must have been taken or partitioned.

Okay, and in this case it was three, wasn't it? Now there must be fewer than five apples in the basket.

So when you subtract from a group of objects, the number decreases in size.

The number at the end must be less than the number at the start of the story.

So it couldn't have ended in seven, because no matter how many you took away from that five, it couldn't have left more than five at the end of the story, could it? Okay, so well done if you noticed that.

Okay, so here's another check for you then.

Alex acts out a subtraction story that starts with six.

Which of these numbers cannot be at the end of his story? Explain why.

So we've got six, A is six, B is seven, or C is five.

Which one of those cannot be at the end of his subtraction story? So pause the video now while you try that.

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

What did you think was at the end of his story? That's right, seven.

Because if he started with six, the number could not increase, could it? So seven cannot be at the end of his story, because if you subtract from a group of objects, it will not increase in size, will it? It will decrease.

Well done if you notice that.

Okay, so Aisha made up a first, then, now subtraction story, but the first number did not decrease in size.

There's Alex and he's saying, "I wonder what number was subtracted." We know when zero is subtracted from a number, the number remains the same, nothing changes.

So Aisha must have subtracted zero.

Okay, so here's a task for the second part of your story.

Okay, so Alex is telling us there what he's going to do and we'll do the same.

"I will use my toys to tell my own first, then, now subtraction stories and Aisha is reminding us, remember to write the equation to represent your story.

How many first, then, now stories can you make up that begin with the number six? And how will you know that you found them all? Okay, so pause the video now while you do that.

Okay.

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

So you may have done this.

Here's Alex, he used toy cars again.

First there was six cars in the garage.

There they are.

Then one car left the garage.

Now there are five cars in the garage, okay? And the equation will be, six minus one is equal to five.

Okay, you could have also had, if you were starting all of your stories with six, six minus two is equal to four, six minus three is equal to three, six minus four is equal to two, six minus five is equal to one and six minus six is equal to zero.

You can work systematically, so you know you've found all the possible equations.

So well done if you did that.

You've worked really hard in today's lesson and now you should feel much more confident telling your own addition and subtraction stories and writing the equations to match them.

So well done.

So let's think about what we learned in today's lesson then.

If starting with and adding or subtracting the same amount, the number at the end of the story will be the same.

When more are added, the number at the start increases and when some are subtracted, the number at the start decreases.

So well done.

So excellent work today.

We've made up lots of stories using toys and perhaps you can make some more of your own up while you are playing as well.

So well done with that, I've really enjoyed working with you today.