Lesson video

Hello, welcome to today's maths lesson with me, Miss Jones, how are you doing today? Hope you're ready to do some maths together, let's get started.

In today's lesson we are going to be solving problems by halving and doubling.

We're going to start off by recapping how we half objects.

Then we're going to look at doubling the amount of objects.

Then you've got your main independent task, and finally, your end of lesson quiz.

For today's lesson, you'll need something to write with and some things right on, such as a pencil and a piece of paper.

If you're not ready for the lesson, go and get what you need and pause the video.

If you've got everything you need, then let's click on.

I've got some ribbon, I've tried to cut this ribbon in half.

How have I cut it in half? Can you explain how you know? Pause the video now to have a quick think about that, okay let's have a look together, now before I decide if I've cut this in half, I need to remind myself what half means when something has been divided in half, the whole has been split into two equal parts, are both my parts equal here? One, we've got two parts that's for sure.

But one part is a lot longer than my other parts, so these parts are not equal.

It's not fair that this ribbon, is a lot longer than this ribbon.

We can't call these halves because they are unequal.

Mmmh If I did want to cut my ribbon in half, what could have I done? What could I have done to help me have a little think? I could have measured the ribbon to try and find out half way.

Aah, look what I've done here, I've used this nonstandard unit of measure, I've used some paperclips.

I can see that this ribbon is one, two, three, four, five, six paperclips long, and this one is one, two, three, four, five, six, paperclips along as well.

Now both of my ribbons are equal length they're the same size.

So now I can say that my ribbon has been cut in half, here we've got some more pieces of ribbon.

I want you to focus on this purple piece of ribbon here, mmmh looking at the others, which other piece of ribbon is half the size, of the purple piece of ribbon.

Have a think about that.

Now I know that if this purple piece of ribbon, was cut in half, we would end up with two equal parts.

One of those equal parts would be half the size, which one of these coloured ribbons, are half the size of the purple ribbon? Well straight away, I don't think it's this pink ribbon.

It's too small.

This yellow piece of ribbon seems too long, So I'm going to rule those two out.

Now I'm not sure if it's going to be the red ribbon or the blue ribbon.

What do you think? Can you point to the one which you think is half the size of the purple ribbon? I'm still not too sure.

What could I do to help me, any ideas? Well, I could line them up let's have a look at my next image aah.

Now I've got them all lined up and I've duplicated some of them.

So you can see what they look like if both hearts were together.

I can see that the yellow one was far too long, as when I have two equal parts it's much longer than the purple one.

The blue one here is also too long.

When I have two equal parts.

The pink one is too short, just like we predicted, but the red one is exactly half the purple one.

I know this because two equal parts, is equal to my whole or my whole has been divided into two equal parts.

It's a lot clearer when we can see them lines up next to each other isn't it? Let's have a look at our big picture, showing Pinocchio and his dad Japanto.

Japanto is in his workshop and he's making some buttons for Pinocchio.

He wants to half this amount of buttons.

Could you help him find half? First of all, let's think about what our whole is.

One, two, three, four, five, six.

Our whole is six buttons.

Do you know what half of six is? Hmm, if I wasn't sure, what could I do to help me find half? What I could share out the six buttons into two groups, or I could divide this in half.

I'm going to a line down the middle of my six buttons, to make two equal groups.

In this group I have one, two, three, and in this group I have one, two, three.

I have three in each group and both my groups are equal.

Therefore, half of six buttons is three buttons.

My turn, your turn.

Half of six is equal to three.

Well done let's move on.

Now Pinocchio's dad wants to have some sewing pins.

How can we find out what half the amount of pins? Mmmh Let's have a think about what our whole is.

One, two, three, four, five, six, seven, eight, nine, 10.

Our whole is 10.

Now we needed to divide 10 into two equal parts.

Now, as there's a few more of these, I think I'm going to use a different strategy, and I'm going to share these into two groups.

I've got two jars here, so I'm going to share my pins equally into the jars, by using a one for you, one for you method.

Okay, I'm going to pick up my pins, and I'm going to put them into the jars.

One for you, one for you, one for you, one for you, one for you, one for you, one for you, one for you, one for you and one for you.

That's all my pins there's no pins left over because I've used a one for you and one for your strategy.

Hopefully these are equal, but I'm going to check.

In this jar I have one, two, three, four, five pins.

In this jar I have one, two, three, four, five.

They are both equal.

10 divided into two equal groups means that I've got five in each group.

Half of 10 is equal to five.

My turn, your turn, half of 10 is equal to five and both my groups are equal size.

Now we've had lots of practise of halving, let's move on to doubling.

What does it mean to double something? Now, if we're doubling, we're doing the opposite to halving, and we need to create two lots of our original amount.

It's just like multiplying by two.

I've got two cubes here, If I want to double it, what, how many cubes would I end up with? Have a think.

And you might have done some doubling before and can double two in your head.

Let's have a look what double two is.

Now I have doubled two and I have four.

I have two lots of what I originally had.

One, two, one, two.

Altogether, I have four.

Two, lots of two is equal to four.

Double two is equal to four.

Can you say that? My turn, your turn.

Double two is equal to four.

Well done.

Okay this time I've got six cubes.

Let's check one, two, three, four, five, six, or we count in twos, two, four, six.

I want to double my amount of cubes.

If you want to, you can use your pencil and your piece of paper, to draw that double six.

All you need to do is draw out our original six and then do another lot of our original to multiply them by two.

Do you want to have pause the video and have a go at that? Okay let's see what double six looks like.

This time I've got two groups of six.

Two equal groups of six.

I've got six here because we've already counted them.

Now I'm going to count in twos to see how many I've gotten together.

We've got six, eight, 10, 12.

I have 12 altogether now, my turn, your turn double six is equal to 12.

Or we could say six multiplied by two is equal to 12.

Can you say that? Now it's time for your independent task.

Here is a table of numbers.

You need to work out what half of them is, the first one is done for you.

Now it says here, you can use some manipulatives to show your answer.

Now you might not have cubes at home and that's okay.

You might want to draw some pictures instead, or use some other countable objects to prove your answer.

You need to think about what half of all of these amounts are.

Okay, I think it's time to pause the video, and have a go at your task.

Once you're done come back to the video, and we'll look at the answers together.

Okay hopefully you've had a go at your independence task.

Let's have a look together at the answers.

Have look through pause the video if you need to, and see if you were correct.

How did you do? Hopefully you've used some manipulatives, some countable objects, or some pictures to help you work out your answers and check them.

If you want to you can ask your parents or carer to share some of those images, or models that you created today and your tables that you worked on.

Once you're done, make sure you go off and complete our multiple choice quiz.

You've worked really hard today guys, well done.