Lesson video

Woo.

Hi everyone.

Sorry, I've just got back from a long walk.

Oh let me take my hat off.

Ah and my scarf.

Oh, do you know what? I got very lost when I was on my walk.

Do you know why? Because I forgot my compass and I couldn't find my way back.

So next time I need to reme- Look what I've just found in my pocket.

I've just found my compass.

We'll talk more about compasses during this lesson, because we're to find out what's a compass actually is and how it works.

I wish I'd known I had it in my pocket because it would have stopped me from getting lost on my walk.

So today we're going to look at how a compass works.

Just before we start, I want to have a think about our think question from last week.

And I asked you this, how might you make the strongest magnet possible? Because in the last lesson on this unit, we had two magnets put together and it held more safety pins than one.

But I wonder what did you think was the possibility for making the strongest magnet possible? I wonder how many safety pins, if I had this many magnets, and I wonder what about if I had a hundred.

I wonder what you came up with with the people that you spoke to, or the thinking that you did about that question.

Okay, so let's get started on today's lesson.

The resources you're going to need are a pen or a pencil, a ruler, a notebook, and if you've got one, you could get a compass.

Don't worry if you've not got one though, because I'm going to show you lots of different examples.

I also have my trusty steed, Lenny the lion here, and every lesson he sits by my screen, listening out to the- Aha, yes.

Are we? They're going to love that.

Okay, he's excited for today's lesson and he's excited for you to see making a compass during the lesson too.

So pause the video and go and get the resources you need, and we'll get started together.

Okay, so in today's lesson, we are going to do the following.

We'll do our star words for our key vocabulary.

Then I'm going to tell you about how compasses were first discovered.

Then we'll see a real compass and I've got a treasure map challenge for you today using the points of a compass.

That's what Lenny's really excited about, and I am too.

So let's get going on our star words.

Are you ready? Star words, star words, star words.

Good job.

There are two already on the screen.

And I wonder, can you remember what the actions were for those two star words? What about the first one, poles.

Can you remember what the action was for that? Well done, poles, because we have the North and South pole.

And what was the action for friction? Can you remember? Well done.

It was rubbing our hands together because it was two surfaces.

Great job team.

Okay, so let's look at our other star words.

The first word is magnet.

Your turn.

Magnet, your turn.

The next word is force, your turn.

Force, let's see those actions, your turn.

Well done, great actions team.

And repel, your turn.

Repel, your turn.

And what was the opposite of repel? What was the opposite of repel? Well done.

It was attract, your turn.

Attract.

Good job team.

I love how you've done the actions really well there.

It really helps them to stay sticky in my mind for those star words.

So we'll come back to those throughout the lesson.

So I'm now going to tell you about how compasses were first discovered.

And in last lesson, there was a stone that we discussed.

Do you remember what it was called? If you're carrying a heavy, load.

Well done.

It was called a lodestone, and it was believed that a form of a compass was first used in ancient China.

Originally they used lodestone, which is the image that you can see on the screen.

It's a piece of stone that has magnetic properties.

We looked at this briefly in the last lesson.

So can you remember when this was discovered, this lodestone? What was the date? Can you remember? Can you tell your screen? Well done, 600 BCE.

That's a really long time ago.

The lodestone was used as a compass by hanging it on the end of a string, and then it would pour, point, sorry, to the North and the South poles.

Wherever you were on the earth, it would point to the North and the South poles.

So you knew which direction North and South was no matter where you were, whether you were in the middle of the desert, whether you're in the middle of the ocean or at the top of a mountain.

Let's just spell the word lodestone together.

Are you ready? L O D E S T O N E.

Lodestone.

Well done team.

So that was the first original use of a form of compass.

And that lodestone helped to point to the North and South poles.

But now you'll see on the screen, something that you probably recognised.

I wonder, have you seen any of these types of compasses before? Hmm, some of you were saying you've seen maybe them on a screen, maybe in a film or even the image on the right on the top of a building.

Well, let me talk you through.

So over time, the use of a compass spread across the world to become what it is today, the modern day compass is a small thin magnet made from steel, which is placed on a pivot.

So pivot means it can turn freely.

The pivot is a small pointed object that the magnet balances on.

And this means that the magnet can spin around easily and point to North.

The image on the left is a beautiful gold compass with a cover that you can open and close to keep it safe.

This looks like one that I might've seen in a film before.

And you might've seen characters keep it in their top pocket, or even on the end of a string.

The middle image is a regular hiking compass sometimes called a thumb compass.

And it's very durable and can be easily packed into a rucksack when going walking.

So you can see in that image in the middle, the North, South, East, and West points, and one of the needles is coloured red.

That's the one that will always point to North.

Now the third image on the right, is not an actual compass.

It doesn't spin and face North, but you can see the North, South, East and West points.

So what they've done here is they've discovered which way North is, and they've put this assembled sign on the top of a roof, sometimes on the top of a barn.

So the North that you can see on the sign is always pointing North because North doesn't change.

Then the arrow on the roof is different to an actual compass.

That will just be the direction of the wind, but the sign has used a compass to find North, and then they've built it to always face in the correct direction.

But why does an actual compass point to North? The reason a compass points to North is because the middle of the earth is filled with iron.

So it behaves like a giant compass.

It, sorry, not a giant compass, like a giant magnet.

But a very weak magnet.

When the magnet on a pivot is free to spin, the compass lines up with the earth's magnetism.

So that's why the needle on a compass will always point to North because it's reacting against the magnetism of the earth.

This is really helpful, if you want to know which way to go if you're lost and you can't use the sun or the stars to find which way to go, just like me on my hike today, I wish I'd known that my compass was in my pocket, I wouldn't have got lost, cause I would have been able to see which direction North is.

Okay, I have got some questions for you to see how well you were listening to that description of where compasses were discovered.

So question one, where was the first compass used? Question two.

What was the first type of compass made from? So before like a compass that we know today, what was that material? What is the middle of the earth filled with? Question four.

What does the earth act like a giant version of? Question five.

Why are compasses helpful? And question six.

What happens if you put a compass next to a magnet? I want you to think about that one carefully, because I said that the earth acts like a magnet, but quite a weak one.

So if you have a compass and then you put a magnet next to it, I wonder what you think would happen.

So question six is a think question, pause the video and write down the answers to those in your notebooks now, and then we'll go through the answers.

Make sure to use your best handwriting, off you go.

Okay, pause the video if you need more time, because I'm going to go through the answers.

Question one, the first compass was used in China.

The first compass was made, sorry, from lodestone.

Question three.

The middle of the earth is filled with iron.

Well done.

Question four.

What does earth act like a giant version of? A magnet, but a weak one.

Don't worry if you've not got that weak on there.

So team for the first four questions so far, give yourself a tick, if you've got those answers correct, Or I want you to edit them and write the correct answer, if you've got them wrong.

It's okay if you made a mistake, don't worry.

It's still cool.

Okay, question five.

Why are compasses helpful? Well, compasses are helpful because it always shows North.

So you can always find your way.

Question six.

What happens if you put a compass next to a magnet? Hmm, I wonder what you thought for this one.

The compass will line up with the magnet rather than the earth's centre, so North will not be true North.

So if I have a compass here, it's pointing North at the moment to the correct direction of North, based on the Earth's magnetism.

But if I take my compass and I put South over here, then my compass is moving because my magnet is stronger than the Earth's magnetism.

Don't worry team.

I'll show you that under the visualizer in a moment, because we're going to talk more about magnets close up.

So let's see a real compass.

Team, just before we do, I'm going to give you an awesome cheer because you're working so hard this lesson, I know some of those questions are quite tricky and there's been a lot of listening, but well done for your hard work so far.

So, let's have a look at a real compass.

As I said previously, the earth's core is made of iron, which acts as a very weak magnet, but strong enough that a compass can always point to North.

The needle, there's a needle inside of a compass.

So this is going to- can you see that? That's an example of a very small needle that you might find inside a compass.

So this needle inside a compass is magnetised.

So it's always pointing North.

However, because a compass is essentially just a magnet.

If it's placed near another magnet, like we've said, it will line up with the magnetism of the nearby magnet.

Let's see how a magnet is used to make a compass.

I'm going to show you one example on a video, and then I'm going to have a go myself.

You can have a go at this if you want to, but team, you need to be really careful because needles can be very sharp and you need to make sure that an adult is supervising you at all times.

So don't try this without an adult.

First of all, let's watch a video.

The first way here is to take the tip of your needle, the point and touch it against the S, the South part of the magnet.

Then take the eye and touch it on the North side right there.

And now your needle is magnetised, and can be used for a compass.

So now you need a floating device for your needle, so it's able to point.

Fantastic.

So, I cut them off there because I want to make sure that we're really clear on what just happened.

He took his needle and he touched it on the North side, and then he touched the other end on the South side of the magnet.

He then placed it in water, to see whether it would point to North.

So why did he use a bit of plastic when he put the needle in the water? I'm going to play the video again.

And I want to think why he might've put the needle on the plastic, into the water.

Let's have another watch.

The first way, here is to take the tip of your needle, the point and touch it against the S, the South part of the magnet.

Then take the eye, and touch it on the North side right there.

And now your needle is magnetised and can be used for a compass.

So now you need a floating device for your needle, so it's able to point.

Okay, why do you think he used a floating device? Can you tell your screen now? Well done.

That's because the needle needs to be able to pivot, so that it can freely point to North.

Team, I'm now going to have a go at this, and I'm going to show you.

Like I said, I don't want you to try this, unless you have adult permission in order to do so, and ideally they need to be doing it with you as well.

So, here I've got my water ready to place the magnet in.

Here I've got my needle, oops, that's my needle.

You can just about see it under the visualizer.

And that's my floating device, I've just got a leaf.

So, one thing I'm going to show you just before we start making it, I'm going to show you, I've got water over here.

I'm going to show you my compass.

So this is my compass here.

So if I turn the plastic around, you can see that North, this small end here always points towards the same direction, even though I'm moving the device.

You can also see a little bubble in there, that's because there's liquid inside it, that's acting as a pivot.

This is my compass that I had in my pocket.

And it will always point to North, no matter which direction I put the device in.

Sometimes it takes a second to adjust, doesn't it team, and you can see it moving.

That's when it's pivoting.

Okay, so let's have a go.

So I've got my needle and I've got my magnet.

Oops, there we go.

So I'm going to put the point of the needle.

I'm going to be really careful not to prick my fingers with it cause it's very sharp.

So I'm going to place that on the North side of my magnet, and then I'm going to turn it around and take the eye and place it on the South side of the needle.

So that it's touched both sides.

I'm just going to do that again, so that it's really, make sure that it's got both ways.

Touch the South with the eye.

Okay, so hopefully now my needle has been magnetised.

I'm going to take my water and I've got my leaf, which is a nice light floating device.

And I'm going to put the needle onto the floating device.

And there you can see it's pivoting, and it's pointing towards North.

If I show you this way, you can see the compass down here, is also pointing to North in that direction, which is the same as the needle.

So I've now made a compass.

This needle is magnetised and it's floating, which makes it able to pivot, and that means that it's able to show me where North is.

Okay, now I have a treasure map, a challenge for you.

I'm just going to turn my visualise off, so that you can see me again, there we go.

Okay, so I'm just going to move my resources so I don't spill everything.

The treasure map challenge is going to really test whether you are really confident with your North, South, East and West of a compass.

Now we need to be really confident with this in order to do the challenge.

So, let's just recap because we haven't talked about this yet.

There's also an East and a West side on a compass, not just a North and a South.

An East and West are perpendicular to North and South.

So have a look at the compass on the screen.

Can you point to where the N is? Can you point to your screen, go on touch it.

There you go.

That's the North.

Now can you take your finger and point to South? Well done.

Now, point to the E and that stands for East.

Now can you take your finger and point to the W? Well done, that stands for West.

And those are our four points on the compass.

There's a way that I like to remember which order those go round the compass in.

So a bit like a clock, it goes North, East, South, West.

Can you say that with me? North, East, South, West.

And I like to remember, never eat shredded wheat.

And that's how I remember, that it goes North, East, South, West.

So do you want to say the rhyme with me? Ready, steady, go.

Never eat shredded wheat.

Say that one more time to your screen without me.

Ready? Never eat shredded wheat, N E S W.

And that helps me to remember the four points on the compass in the correct order.

They go round in a clockwise direction.

So now we are really confident with the direction of a compass and our four points.

I'm going to show you a treasure map.

I would like you to use your compass points, to get me from the beach all the way to the cross, where the treasure is, but I figured out a route, but I just need to write down the directions so that someone can read it.

You need to make sure that you're not straying off from the route, in case you get attacked by pirates or eaten by snakes.

So each step we'll have a set of squares and a direction.

So you can see where the dotted line starts from my route, which direction do I first start travelling? Can you have a look? If it's to the left of your screen, which direction is that? Is that North, East, South or West? I'm going to go back to that compass so that you can have a look.

Which way is left? Well done, It's West.

So my first direction, I need to travel is West.

Now, can you count with your finger, how many squares left do I need to go? One, two, three.

So I need to move three squares and I need to travel in a West direction.

So this is what your steps will look like.

Move three squares West.

What would the next one be? So if you've got three squares left, I then need to travel, I think I need to travel up one square.

Which direction is up? Let's have a look at the compass.

Upwards is North.

So how many squares North? Can you have a look at your screen? How many squares is that? I think that's one square.

So move one square North.

I hope you enjoy having a go at this.

I'd like you to see if you can complete those steps and get me all the way to the treasure map.

Then why don't you show a grownup at home or one of your brothers or sisters, or even one of your friends at school.

That way you can get them to travel on your directions and see if they make it to the treasure.

You could even have a go at making up your own wherever you are, and setting a treasure map for yourself.

You could even draw one.

Okay, so those are the steps I'd like you to follow, pause the video either on the steps or on the treasure map and have a go at your task now.

Okay, pause the video, if you need more time to complete your treasure map and have a double check that you haven't missed any of the steps.

Well done team.

I'm going to give you a rainbow cheer, which goes like this.

Ah because you've worked so hard this lesson.

I've got a final think question for you and Lenny the lion and I, are really excited for you to have a think about your think question.

Why were compasses so helpful to people sailing in boats, no matter what the weather was like? So if Lenny the lion and I, went on an adventure and we took a boat, we were in the middle of the ocean.

Why would a compass be helpful for us if it was stormy, stormy weather, we couldn't see anything, or even if it was bright sunshine and we could see land around us so we knew where we were.

Why would a compass be helpful in that situation? I wonder, can you have a think and tell your screen? And then later I'd like you to speak to somebody about it and have a scientific conversation.

I'd love to know what you thought.

So well done today team.

You've done so well at learning about what a compass is.

I'm really excited for the next lesson, were we're going to continue our work on magnetism.

Well done everyone and see you next lesson.

Bye.