Lesson video

Hello, my name's Mrs. Hopper and I'm really looking forward to working with you in our maths lesson today.

We are going to be thinking all about place value, numbers up to a 100 and how we can apply that and other strategies to adding and subtracting.

So I hope you're ready to work hard and have some fun in our maths lesson today.

So in this lesson in our unit of securing place value to a 100 and applying to addition and subtraction, we're going to be using number facts to 20 to add multiples of 10.

And we're going to be bridging 100.

So key words in our lesson today are addend and bridging 100.

So let's have a go at saying those.

I'll take my turn, then it'll be your turn.

So my turn addend your turn.

My turn bridging 100, your turn.

Well done.

Let's have a look at what those words mean.

So an addend means any of the numbers that are being added together.

So for example, in 100 plus 30 equals 130.

The 100 and the 30 are the addends.

So the addends sum to make the total, so addend plus addend is equal to our total 100 plus 30, our addends are equal to 130.

Bridging 100 means partitioning one addend to make a number one to a 100 and then adding the remaining part.

So it's really useful when we've got two numbers that are going to have a sum or a total that goes over 100.

So watch out for those keywords as we go through our lesson today.

There are two parts to our lesson.

In the first part we're going to use number facts to 20 to add multiples of 10.

And then in the second part we're going to focus in on that bridging 100 to add multiples of 10.

So let's start by using some number facts to add multiples of 10.

And in our lesson today you are gonna meet Izzy and Jacob who are gonna help us with our learning.

Okay, so we've got lots of base 10 blocks there on the screen.

And we are going to be using them to help us to think about calculating 50 plus 70.

But I want you to have a think what number fact could help you to calculate 50 plus 70.

So it might be helpful to think about how many tens we've got.

So you may have looked at these multiples of 10, think about how many tens are there.

So I know that 50 is the same as five tens and that 70 is the same as seven tens.

So five tens plus seven tens.

Does that remind me of something else I can think of? Well, I know that five plus seven is equal to 12, so I wonder if five plus seven is going to help me here.

So we'll be just thinking about our 50 and our 70 as a number of tens.

So let's have a think about that again.

So if we know that five plus seven is equal to 12, we also know that five tens, there they are plus seven tens and there are our seven tens is equal to 12 tens.

So altogether we've got 12 tens, five tens plus seven tens.

And we know that five tens is equal to 50.

So we know that 50 plus our seven tens, which is 70 must be equal to 120.

Because 12 tens is the same as is equal to 120.

So 50 plus 70 is equal to 120, and we can use our known factor five plus seven is equal to 12 to help us.

There we go.

Five plus seven can help you to calculate 50 plus 70.

When we use our place value knowledge and think of 50 as five tens and 70 as seven tens.

So what number fact would help you to calculate 60 plus 50 I wonder? Well Izzy says six plus five can help you to calculate 60 plus 50 because 60 is six tens and 50 is five tens.

So if I use six plus five, I can work out what 60 plus 50 is.

So let's have a look at that.

So we've got six plus five and six plus five is equal to 11.

So six tens plus five tens must be equal to 11 tens.

So what do I know about 11 tens? Well that's 10 tens and one more 10 which is 110.

So 60 plus 50 must be equal to 110.

So I've used a known fact within 20 to help me to work out how to add multiples of 10.

One more to have a think about, 80 plus 40, I've got my 80 on the screen here already.

How would we calculate 80 plus 40? And there are my extra four tens, four tens, eight tens plus four tens does that give me a clue? It does, eight and four.

Eight tens and four tens so I can think about using my known factor of eight plus four.

So what do I know about eight plus four? I know that eight plus four is equal to 12.

So eight tens plus four tens must be equal to 12 tens.

So 80 plus 40 has got to be equal to that 12 tens.

What do I know about 12 tens? Well I know that that's 10 tens and another two tens.

Two tens is 20, so 120.

So 80 plus 40 is equal to 120.

Okay, time to check your understanding.

Jacob's done some calculations here and he says I think 80 plus 50 is equal to 113 because eight plus five is equal to 13.

The answer must be bigger than a 100.

So it must be 113.

"Do you agree?" He says, and there's his working out.

So pause the video and see if you agree with Jacob.

What did you think? Izzy says, no, I don't agree with Jacob.

Eight tens add five tens is equal to 13 tens and 13 tens is 10 tens and three more tens is 130, not 113.

So eight plus five is equal to 13.

Jacob was right.

Eight tens plus five tens is equal to 13 tens.

But 80 plus 50, if we express that as a three digit number, 80 plus 50 is equal to 130.

It's 13 tens, not just the 13 added onto 100.

So did you agree with Izzy there? And can you follow the way Izzy was thinking? So we need to be careful when we're adding to make sure that we are thinking about that number of tens and expressing our number as a number of tens and then as a three digit multiple of 10, a number of tens.

So sorry Jacob, if you weren't right this time.

So this time we've got a missing addend, haven't we? 90 plus something is equal to 120.

So this time I'm working out one of the parts, not my whole.

So what number fact is gonna help me? I've got to do 90, and here's my 90 plus an unknown number of tens here to equal 120.

Well let's think about that number of tens, I've got nine tens and I'm looking for another number of tens to equal 12 tens 'cause 120 is equal to 12 tens.

So can I use something about nine plus hmm equals 12? What do I know about that? What do I need to add to nine to equal 12? Well I know that nine plus three equals 12 Jacob's reminding me here.

Nine plus three is equal to 12.

So I know that 90 plus 30 is equal to 120.

So let's have a think about that.

90 plus 30 Jacob says, let's just check our thinking.

So nine plus three is equal to 12.

So nine tens plus three tens must be equal to 12 tens.

And we know that 12 tens is one group of 10 tens, so 100 plus two more tens plus 20 is 120.

So 90 plus 30 is equal to 120.

So we can use our number facts, to help us to work out a missing whole, a missing sum, or we can use them to work out one of our missing addends.

A bar model can help us as well, 'cause a bar model often helps us to find out what is it that's missing, is it a part or is it a whole? So this time we've got 80 plus 60 is equal to something.

So we know this time, we know our parts, don't we? So 80 plus 60 are our parts and we are missing our whole.

And we can see we've got our base 10 blocks there to help us to see 80 plus 60.

So I wonder what fact we're going to use.

Well Izzy says, I know that eight plus six is equal to 14.

So she spotted that 80 plus 60 is eight tens plus six tens.

So we can use our knowledge of eight plus six.

So eight plus six is equal to 14.

So eight tens plus six tens must be equal to 14 tens.

So 80 plus 60 must be equal to 140.

So our whole, our missing hole is 140 and we've used the number fact eight plus six equals 14 to help us to work it out.

Have a look at these three bar models.

What do you notice about them? Well there's some things that are the same about them aren't there? But there are some things that are different.

Let's have a think.

Izzy says what's the same about the representations? Jacob says they all use the number fact six plus five is equal to 11.

They all use it in a slightly different way, let's have a think.

So Izzy says, well what's different about the representations? Jacob says, the first bar model represents ones, six ones plus five ones is equal to 11 ones.

So we are just thinking about our number ones within 20.

So we are just thinking about those the six and the five as six ones and five ones, and we know that they add together to equal 11.

The middle bar model Jacob says represents the number of tens.

So we are taking that knowledge and applying it to a number of tens.

So if six plus five is equal to 11, then six tens plus five tens is equal to 11 tens.

And then the third bar model that represents those multiples of 10.

So we know that six tens is equal to 60, five tens is equal to 50 and 11 tens is 10 tens and another one tens so 100 and tens.

So 60 plus 50 is equal to 110.

So we've used one number fact and we've used it to help us to add multiples of 10.

Okay, so Jacob says, "This time these bar models use the number fact seven plus nine is equal to 16." So there's our number fact that we are using.

So can we use that to complete the missing numbers in our bar models? Let's have a look.

So in our first bar model, we're missing a part.

We know that the hole is 16, we know that one part is seven.

If we know that seven plus nine is equal to 16, then our missing part must be nine.

Seven plus nine is equal to 16.

In the middle bar model, we know that our whole is 16 tens and we know that one part is nine tens.

So we know that we are using the number fact seven plus nine or nine plus seven is equal to 16.

So if we know about the nine, then the other part is the seven.

So our missing part here must be seven tens.

'cause seven tens plus nine tens is equal to 16 tens.

So in our last bar model we are given the two parts, we've got 90 and 70.

So let's think we were using that seven plus nine.

So how can we use that to help us to interpret that final bar model? Well I've got 70, which is seven tens and 90, which is nine tens.

And so if I combine my parts, I'm going to get my whole, which is my 16 tens.

And we know that 16 tens is one group of 10 tens which is 100, six more tens which is 60, so it's 160.

90 plus 70 is equal to 160.

So one more together and then we want to check your understanding.

We're going to use number facts to 20 to complete the calculations.

So we've got seven plus six is equal to something.

Seven tens plus six tens is equal to something.

70 plus 60 is equal to something.

Can you see how that seven plus six is going to help us? So seven plus six is equal to 13, well done.

So if I know that seven plus six is equal to 13, I know that seven tens plus six tens must be equal to 13 tens.

What do I know about 13 tens? Well I know I've got a group of 10 tens which is equal to a 100 and I've got three more tens, I've got 30 more.

So 70 plus 60 is equal to 130.

So in my bar model I have my two parts which are 70 and 60 and my whole is 130.

So on the right hand side you've got some calculations to complete that are linked to the number fact nine plus six.

So pause the video and have a go at filling in those gaps and then we'll talk about them.

How did you get on? Did you know that nine plus six is equal to 15? Well done, so we can now use that factor to help us.

'cause if nine plus six is equal to 15, nine tens plus six tens must be equal to 15 tens and 90 plus 60 must be equal to well 15 tens.

One group of 10 tens which is a 100 plus five more tens, which is 50.

So 90 plus 60 is equal to 150.

The whole in our bar model is 150.

Well done.

Time for some practise.

So you are going to complete the missing numbers in these bar models.

So what have we got missing? We've got some holes missing, we've got a part missing.

We are thinking about this in different ways, thinking about our number fact, our number of tens and then our multiples of 10.

So complete the missing numbers is your first part of your task.

And then we've got some more missing numbers.

So we've got some bar models, but also we've got some calculations for you to complete.

So pause the video, have a go at these questions and then we'll have a look at them together.

How did you get on with your missing numbers? So let's have a look.

Our first bond model had a missing whole, didn't it? So we had nine plus four is equal to 13.

So then we also had missing whole in our middle one.

And we know that if nine plus four equals 13, then nine tens plus four tens is equal to 13 tens.

And in our final bar model, we had a missing part, didn't we? But we can still use that same number fact because if nine tens plus four tens is equal to 13 tens, we know that 40 plus 90 must be equal to 130.

So the calculations are all based on that number fact.

Nine plus four is equal to 13.

And then you had to complete some missing numbers.

So in the first one we had a bar model with the two parts were 90 and 90, okay? And we had to work out how many tens we had altogether.

So did you spot that 90 is nine tens and another nine tens means we've got 18 tens altogether.

So part b we had a missing whole, 60 plus 70.

So if we think about six plus seven is equal to 13, then our six tens plus seven tens is 13 tens and 13 tens is equal to 130.

So have a look through and see if you got the rest of your answers correct for this part of your task.

Okay, well done, great work In that first part of our lesson, let's have a look into our second part.

We're going to be thinking about bridging a 100 to add multiples of 10.

So adding some similar numbers but thinking about it in a different way this time.

So we've got our 70 plus 50, I think we've looked at this one already, haven't we? So 70 plus 50 is equal to mmh.

So we know our parts, we're going to combine them to find our whole.

So Jacob says' "We've been using number facts to add." So seven tens plus five tens is equal to 12 tens, I can do that this way.

But we're going to look at a different strategy this time.

We are going to make and bridge 100.

So let's have a look at what that means.

So let's think about our 70.

What do we need to add to 70 to make 100? Well 70 plus 30 is equal to a 100, but where can we find 30? We're doing 70 plus 50.

Well let's have a look at our 50.

We can partition 50 into 30 and 20.

Aha, there we go, look at that.

So if we add our 30 to our 70, we can make 100.

So 70 plus 30 is equal to a 100.

And now we add the 20 that's left over.

'cause we partitioned our 50 into 30 and 20.

And we know that 100 plus 20 is equal to 120.

So 70 plus 50 is equal to 120.

And we've done that by bridging through a 100.

So we knew that 50 was equal to 30 plus 20.

We knew that 70 plus 30 was equal to a 100, but then we mustn't forget the other 20 that was part of our 50.

So 100 plus 20 is equal to 120.

Let's represent this in a slightly different way.

We're going to use a part part whole model to help us.

Can you remember that those parts, the bits that we were adding together were called the addends.

So 60 and 50 are our addends.

So we're going to partition our addend of 50 to see if we can bridge through a 100 again.

So we've got 60 plus 50, what would we need to add to 60 to total 100.

Can you think? Well 60 plus 40 is equal to a 100.

So that would help us to bridge a 100.

So can I partition my 50 into 40 and something I can, because we know that 50 can be composed of 40 and 10.

So 50 is equal to 40 plus 10.

So I can now use the 40 part to combine with my 60 to bridge a 100.

So 60 plus 40 is equal to a 100.

And there it is, so my 60 and then four tens from my 50.

So 40 out of my 50.

And what else have I got to add in? I've got one more 10 to add in.

100 plus 10 is equal to 110.

So 60 plus 50 is equal to 110.

So we've got 90 plus 50 here and Izzy's giving us a bit of help.

So Izzy says,"On the part part whole model, we can see the addend 50 is going to be partitioned." So remember that those numbers that we add together to get our total, to get our whole are called our addends.

So they're like the parts, aren't they? So we are going to partition 50.

So she says, "What if we partition 50 into 20 and 30? Is that gonna help us?" So if we partition 50 into 20 and 30, does that help us to bridge a 100? I'm not so sure 90 plus 20 doesn't equal 100 90 plus 20 equals 110.

I could use that, but we are thinking about bridging a 100 'cause that makes things really easy for us.

'cause we get to a 100 and then we add the remaining tens, don't we? So 20 plus 90 is equal to 110, not a 100.

So we can partition 50 so that we can create a 100.

So we can do this better.

We know that 10 plus 90 is equal to a 100.

So let's partition our 50 in a different way.

If we partition our 50 into 10 and 40, then we know that we've got our number bond to a 100.

We can bridge through a 100 because we know that 90 plus 10 is equal to 100.

And then we've got our extra 40.

So 100 plus 40 is equal to 140.

Izzy says, "We can also use a number line to show this." So notice that the addend 50 is partitioned into 10 and 40 to bridge a 100.

So 10 plus 90 is equal to a 100.

Let's look at that on the number line.

So here's a bit of a number line.

So we've got 90 and we are adding 50 remember.

So we're going to add 50 onto 90, but we're going to do it by partitioning the 50 and bridging through a 100.

So just like we did on the part part whole model, we're going to add that 10 first.

So 90 plus 10 is equal to 100 and we know that we partitioned the 50 into 10 plus 40.

So we can add the 40 now and we get to 140.

So 90 plus 50 is equal to 140.

We can use the part part whole model to help us to partition.

And then we can also see that bridging through a 100 on the number line as well.

Okay, so let's have a look at this one.

We've got 80 plus 50 this time.

50 is getting a getting mentioned quite a lot, isn't it? So this time we are doing 80 plus 50.

So how could you partition 50 this time to bridge 100? So Izzy says' "Partition the addend 50 into 20 plus 30 because she knows that 80 plus 20 is equal to a 100.

So we're gonna partition our 50 into 20 plus 30.

And we're gonna show this on the number line as well as using the part part whole model.

So let's have a look at these two together.

So there's our 80 and we're going to add 20.

So 80 plus 20 is equal to a 100.

And we know that using the part part whole model, we can show that as well.

80 plus 20 is equal to a 100.

What else have we got to add? So we partitioned our 50 into 20 plus 30.

So we've got that extra 30 to add on, haven't we? So 100 plus 30 is equal to 130.

So we can show that on the number line.

We've added our 50, but we've added it a jump of 20 and then a jump of 30 and our answer is 130.

80 plus 50 is equal to 130.

Now that we've got 80 plus 70 here and we can actually partition either addend, we don't have to partition the second one, it doesn't really matter which one we partition.

There might be a fact that you know better or that springs to your mind first.

So let's have a look at partitioning a different addend each time we work this out.

So let's start with this top 180 plus 70.

And we're going to partition the 70 into 20 and 50 because then we've got that 80 plus 20 is equal to 100.

So the addend 70 can be partitioned into 20 plus 50, 80 plus 20 is equal to a 100, and then 100 plus 50 is equal to 150.

But we could decide to partition the 80, the addend 80 instead.

So let's have a look at that.

So the addend 80 can be partitioned and this time we're gonna partition it into 30 and 50 because that 70 plus 30 is going to give us our 100 again.

Bridge through a 100.

So 70 plus 30 is equal to 100.

And then we've got the 50 to add on, 100 plus 50 is equal to 150.

And of course the sum is the same, the total is the same, but we can get to that total by partitioning either of our addends.

Whichever one we decide works best for us.

Okay, so let's have a look at a problem in a context.

I've got two jugs of juice here and if you added the two amounts of juice together, how much juice would you have? Oh, we've gotta find out how much is in each jug first, haven't we? So that involves looking at our scale and thinking, well, I can see if I have a count through.

I've got 10 divisions up to a 100, and I know that there are 10 tens in a 100, so I'm counting in tens.

So my first jug has got 90 millilitres of juice in it and my second jug has got 40 millilitres of juice.

So I've now got to add those together.

So I've got to do 90 plus 40.

And Jacob says, "We can add 90 millilitres and 40 millilitres to find the total." So let's have a look at that edition.

Lots of different ways I can think about it.

I know that I can partition my addend 40 to give me a number onto a 100 so I can bridge through a 100.

So I can show that on the number line or I can use a part part whole model to partition one of the addends.

So let's have a look at those two ways of working it out.

So I'm to put 90 on my number line and I'm adding 40, but I'm going to partition my 40 into 10 and 30 because I know that 90 plus 10 is equal to a 100.

And I've then got another 30 to add, which will take me to 130.

And you can see on my part part whole model that I've partitioned my 40 into 10 plus 30 so that I can add my 90 plus 10 to give me 100 and then add on my extra 30 to equal 130.

90 plus 40 equals 130.

So they have 130 millilitres of juice all together.

So this time we've got a missing addend.

I know that something plus 40 is equal to 110.

I've also got a clue there that I've partitioned my 40 into 30 plus 10, but I've got to work out what the missing addend is.

But I do know that I'm trying to bridge through a 100.

So Izzy says, "To find the missing addend, we can use the part part whole model to complete the calculations." So something plus 30 is equal to 100.

So what do we know? And then we know that that number plus 40 is equal to 110.

So what do we know about our number bonds to 100? 30 plus what is equal to a 100? Well I know that 70 plus 30 is equal to a 100 and then I've still got 10 to add on from my partitioned 40.

And a 100 plus 10 is equal to 110.

So I know that 70 plus 40 is equal to 110.

My missing addend is 70.

This time I've got a missing part of my addend.

So I know I've partitioned my 60 into something and 30, in order to add 70 plus 60.

And remember we are partitioning so that we can bridge through a 100.

So what would be a good number to have partitioned my 60 into in order to bridge through a 100? Let's see what Jacob says.

Jacob says, "We have two addends, 70 plus 60 and we can calculate the missing part by partitioning the 60.

So what do we know about 70 add something is gonna be equal to a 100.

Or to bridge a 100, we partition the addend 60 into 30 and 30.

So that 70 plus 30 is equal to a 100.

So our missing part here is 30.

70 plus 30 is equal to 100 and 100 plus the extra 30 is equal to 130.

Okay, so one to have a look at together here and then one for you to have a go at on your own.

So this time we know that we are adding 70 plus 50 and we need to think about how we're going to partition the 50, so that we can bridge through a 100.

So let's have a think.

We've got 70 plus 50, 70 plus something equals a 100, but I know that 70 plus 30 is equal to a 100.

So I'm going to partition my 50 into 30 and 20.

So 70 plus 30 is equal to 100.

And then if I've partitioned my 50 into 30 and something I've partitioned it into 30 and 20 is 30 plus 20 is equal to 50.

So 100 plus 20 is equal to 120.

So I can write this out as an equation.

70 plus 50 is equal to 70 plus 30 plus 20.

That 30 plus 20 is our 50 partitioned to help us to bridge through a 100.

A 100 plus 20 'cause our 70 plus 30 is equal to a 100.

So 70 plus 50 is equal to a 100 plus 20, which is equal to 120.

So have a look at the problem on the right hand part of the screen and complete the part part whole model and write those equations for 80 plus 50.

Pause the video and then we'll have a look at it together.

Okay, how did you get on? What did you decide to partition 50 into this time? So looking at that 80 plus something equals a 100, well it's not much different to the other one except we sort to want to think about the 21st because we know that 80 plus 20 is equal to a 100.

And so our other part for our 50 must be 30.

So 80 plus 20 is equal to a 100 and we've got our other 30 to add in.

So let's have a look at the equations then.

We can say that 80 plus 50 is equal to 80 plus 20 plus 30.

20 plus 30 is how we've partitioned the addend 50.

So we know that's 50, but we've partitioned it to help us to add.

So 80 plus 50 we can also say is equal to 100 plus 30.

We've combined the 80 and the 20, we've still got the 30 to add.

And 100 plus 30 is equal to 130.

So 80 plus 50 is equal to 130.

Okay, so some for you to have a look at now.

So we know that we're adding 60 plus 50 and then we're adding 70 plus 50.

So use those part part whole models to think about how you are going to partition the 50 in each occasion, in order to help you to bridge through 100.

And then see if you can fill in the blanks in the equations below.

So pause the video and then we'll have a look through them together.

How did you get on? So in the first one we're adding 60 and 50.

So what do we need to partition our addend 50 into? So we get a number bond to a 100 with 60.

So 60 plus what equals 100? 60 plus 40, excellent.

So if we partition our 50 into 40 and 10, we can use the 40 to help us to bridge through 100.

So let's have a look at the equations for that one.

So 60 plus 50 is equal to 60 plus 40 plus 10, and our 60 plus 40 is equal to a 100.

So that's equal to 100 plus 10 and 100 plus 10 is equal to 110.

Excellent.

Let's have a look at 70 plus 50.

So this time our 40 plus 10 for partitioning isn't really gonna help us.

Is it because 40 plus 70 isn't a number bond to a 100.

So to bridge through a 100, what do we need to add to 70? Well we need to add 30.

So if we partition our 50 this time into 30 plus 20, we can use the 30 to make a 100 with the 70.

So 70 plus 50 is equal to 70 plus 30 plus 20, and that is equal to a 100 plus 20 because 70 plus 30 is equal to a 100, and a 100 plus 20 is equal to 120.

So 70 plus 50 is equal to 120.

So some for you to have a go at, to complete the calculations and think about how you would partition one of the addends to help you to bridge through 100.

So in the second part, you haven't got the part part whole models, but you might want to draw some for yourself to help you.

Because here we've got some missing addends.

So you are gonna have a think about how you can use what you know about number bonds to a 100 and bridging through a 100 and partitioning to work out what those missing numbers are.

So pause the video and have a go and then we'll look through the answers together.

How did you get on? Did you work out how we could partition these numbers to help us bridge through 10? Let's have a look at a 80 plus 60.

So I want a number that goes with 80 to equal a 100.

So I know that 80 plus 20 is equal to 100, so I can partition my 60 into 20 and 40.

80 plus 20 is equal to a 100 and a 100 plus 40 is equal to 140.

So b asked us to add 90 and 60, 90 plus 60 well I know that 90 plus 10 is equal to a 100.

So I'm going to partition my 60 into 10 and 50.

90 plus 10 is equal to 100.

100 plus 50 is equal to 150.

C asks us to add 90 and 40.

So again, what's gonna go with 90? Well, 90 plus 10 is equal to a 100.

So I can partition my 40 into 10 and 30.

90 plus 10 is equal to a 100.

A 100 plus 30 is equal to 130.

And finally for D 80 plus 40, so 80 plus 20 is equal to a 100.

So I can petition my 40 into 20 plus 20.

Doesn't matter which way round I write this one because 20 plus 20 is equal to 40.

So 80 plus 20 is equal to 100 and 100 plus 20 is equal to 120.

I hope you had fun partitioning your addends there.

So here we had some calculations to complete with lots of missing numbers.

So I'm gonna give you a moment just to check through and then we'll just talk through A just to see how we went about thinking about it.

So just pause the video now and check through your answers.

So let's just talk through a.

So a was 80 plus, hmm equals 80 plus Hmm plus 40.

So we were trying to add 80 plus 60 and we knew we'd partitioned our 60 into something and 40 and it would be a good idea to partition it into 20 plus 40 because we know that 80 plus 20 is equal to 100.

So I hope you were able to use your knowledge of number bonds to 100 and partitioning in order to help you to work out what those missing values were in those equations.

Well done.

We've got to the end of our lesson today and thank you for all your hard work.

So what have we learned about today? Well, we've learned in that first part, we learned that number facts to 20 can be applied to adding multiples of 10.

So we use known facts within 20 and thought about the number of tens that represented and then what that represented as a multiple of 10.

So we also looked at some other number facts that would help us to bridge 100.

So we were looking at pairs of multiples of 10 that totaled 100 and we used the part part whole model and that helped us to visualise partitioning one of the addends in order to bridge 100.

And we looked at that on the number line as well to help us think about it.

So we know that we can use number facts to 20 to add multiples of 10 and we can use number facts to help us to bridge 100 in order to add multiples of 10.

Thank you for your hard work today and I hope to see you again soon.

Bye.