Lesson video

Hello, I'm Mrs. Judah And I'm going to be taking your lesson today.

Let's go through the practise activities from last lesson.

Did you use your generalisations to help you solve the equations? Let's have a think.

Hmm.

When I add 2, to an odd number, it gives the next odd number and the next odd number after 3 is 5 2 + 9 Now I know I can change the order of the add ends and the sum remains the same.

So it's easier to think about it as 9 + 2 And the next odd number would be 11.

Now I've got an even number.

So when I add 2 to an even number, it gives the next even number.

So 6 + 2, the next even number would be 8.

8 = 6+2.

I've got an odd number again, and I'm going to switch the order of the add ends.

So I've got 5 + 2.

And the next odd number after 5 is ,that's right.

7 I've got subtracting now or subtracting 2 from an odd number, gives the previous odd number.

So the odd number before 9 is 7.

Ooh.

Now I've got an even number, but I've got to subtract 2.

So that's going to give me 0, Put your hand up.

If you had to go at the challenge questions, let's have a look at this.

So it's shown slightly differently here.

We've got 8.

We can see that we're adding 2 and we need to know what our missing number is, what the sum is.

So I know that when I add 2 to an even number, I get the next even number.

So that will be 10.

That's correct.

The next one.

This is subtraction now.

And it's an odd number.

So when I subtract 2 from an odd number, I get the previous odd number and the previous odd number is 3.

All this is a little bit more tricky.

Now I've got 2 + 6.

Wow.

I know if I change the order of the ad ends, the sum remains the same.

So I'm going to think of it as 6 + 2.

So that will be the next even number, which is 8.

Fantastic.

So let's have a look at the facts that we already know 1 + 3.

Ooh.

Wow.

I know that adding 1 gives 1 more.

So I'm going to change position of the add ends and the sum will remain the same.

So I'm going to think of it.

It's 3 + 1.

And it's 1 more.

So that will be 4.

Now let's have a look at the next one , 2 + the, or we've done adding 2.

We know that when we add 2 to an odd number, it gives us the next odd number.

So I can just switch the add ends around.

And that means that it will be the next odd number after 3, which is 5 that's right All 3 + 3.

These are doubles when both our add ends are the same.

We're doubling and double 3 is 6.

That's right? Well, I've got 4 + 3.

Well, 4 + 3 is very close to 3 + 3.

Isn't it? It's called a near double.

So it's going to be 1 more than 6.

That's 7 Excellent.

So near double hmm we haven't seen this one, 5 + 3.

Okay.

So I'm thinking about 5 + 3.

So I've put 5 in our 10 frame because I'm thinking about 5 and a bit.

So then I want to think about the 3 that I'm adding.

Ooh, that would be 2 less than 10.

So I could use that strategy to think about what 5 + 3 is.

I could also think about another strategy because we've just done adding 2 and 3 is just 1 more than 2.

So I could think about the next odd number after 5 would be 7, but it's 1 more than 7 it's 8, 5 + 3 is equal to 8.

Let's have a look at that in a part part, whole diagram.

I can see that 5 + 3 is equal to 8.

5 is 1 part 3 is another part and the whole is 8.

Hmm.

What's my missing number here then.

Did you say it was 3? What about if I did 8 minus 5? What would that give me ? Did you say that would be 3 ? 8 minus 5 is equal to 3.

What's the missing number in this part Part whole? did you say 5? What about if I asked you what is 8 minus 3? What's 8 minus 3.

Is it 5? Let's have a look at these equations.

I bet we can do them really quickly, but we're just going to have a look at them.

First of all, what do you notice about all of these equations? Did you notice that they're all linked and that all going to use the numbers 8 to 5 and 3.

So let's see if we can say them really quickly together.

We're going to say the whole equation, including the missing number.

Are you ready? 5 + 3 is equal to 8.

3 + 5 is equal to 8.

8 is equal to 5.

+ 3 8 is equal to 5 + 3, 8 minus 5 is equal to 3 8 Minus 3 is equal to 5.

You can pause the video and have a look at all these equations and see how they're all linked.

What about if we look at this now, 6 + 3, what can we use to help us solve this really quickly? Did you think about this? This fact 6 + 4 is equal to 10.

We know this fact because we know our number bonds to 10 and 6 + 4 is very close to 6 + 3, but it's just 1 less.

So what is 1 less than 6 + 4? That's right.

It's 9, 6 + 3 is equal to 9.

You might also think about it because we also know that 3 is 1 more than 2.

And we have just learned that when we add 2 to an even number, it gives us the next even number.

So that would be 8 and 1 more than 8 is 9 let's have a look at it with a part, part, whole model.

Can you see how 6 is one part 3 is another part and 9 is the whole 6 + 3 is equal to 9.

What's my missing number.

Did you say it was 3? What about if I asked you what? 9 minus 6 is, Did you say it's equal to 3, 9 minus 6 is equal to 3.

Have a look at this diagram.

What's my missing number? Did you say 6? What about if I asked you what is 9 minus 3? Did you say 9 minus 3 is equal to 6? I bet we can look at these equations and do them really quickly.

First of all, what do you notice about the equations? Did you notice that that all linked and that all going to use the numbers? 9, 6 and 3.

Should we see if we can do them really quickly? We're going to say the whole equation together.

Are you ready? 6 + 3 is equal to 9.

3 + 6 is equal to 9.

9 is equal to 6 + 3 9 is equal to 6 + 3, 9 minus 6 is equal to 3.

9 minus 3 is equal to 6.

You're so good at these.

Let's see if we can do these really quickly.

You can pause the video and see how quickly you can do them off you go.

Okay Should we see if we can fill in the missing numbers really quickly? What's our first missing number.

That's right.

It's 8.

8 is equal to 5 + 3.

What's our next missing number 3.

That's right.

8 minus 5 is equal to 3.

And our next missing number is 3 again.

8 minus 3 is equal to 5.

Okay.

Next pair of equations.

Can you pause the video and solve these really quickly? Did you have a go? Let's see if we can do it quickly.

What's the first equation.

That's right.

6 + 3 is equal to 9.

So what's 3 + 6.

That's also 9.

Did you notice that the add ends were the same? It's just that they were in a different position and the last equations.

I bet you don't even need to pause the video now what's our missing numbers.

9 minus 3 is equal to 6 and 9 minus 3 is equal to 6.

You are doing these so quickly.

Fantastic work.

This is the practise activity.

I'm going to leave you with today.

There are 2 word problems here.

Can you write the equation that goes with each problem? And can you draw a part part whole model as well? The first question says there are 9 children.

6 of them have scooters.

How many of them don't have scooters? You could draw the part part, whole model first, and that will help you to know how to do the equation.

The second question says, I need 5 metres of fabric to make some costumes.

I need 3 metres of fabric to make some curtains.

How much fabric do I need all together? You've worked really hard today and you are doing fantastic.

Remembering your number facts, well done everybody.