Hello, everyone and welcome to today's science lesson.

I'm ever so excited about learning with you today.

And today's lesson is within the unit: Simple forces including magnets.

We're going to be learning today about how things move across different surfaces.

Is everyone ready? Our learning outcome is: I can plan an investigation to compare how things move on different surfaces.

So we're going to be thinking about do objects all move in the same way across different surfaces? And we're going to be using our working scientifically skills today, and we're going to be planning how to compare how objects move so that we can find out if they all move in the same way or if there are any differences.

Here are the keywords for today's lesson.

So have a quick read down and just be thinking to yourself, "Have I heard of these words before? Do I know what any of these words mean?" Or are there any words that you think, "Hmm, I might need to think about these a little bit more.

And maybe these are new words for me that I'll be learning about today." So moving on to the keyword definitions, and again, all of these keywords we'll be talking about in the lesson today, so have a look at their definitions now, but we will be coming back to these throughout the lesson itself.

So you can see we've got surface, and rough and smooth.

Now this is a tricky one.

We are thinking about a comparative test.

And finally we need to think about what it means to compare.

And that was the learning outcome, wasn't it, from today's lesson to be able to compare.

So that's a really important word in the lesson today.

Our lesson today is in three parts, and the first part we're going to be thinking about how surfaces can be different.

So let's begin by thinking about surfaces.

Now, surface is one of our keywords today.

So you will already have been thinking about what a surface is.

So are you confident in saying that a surface is the top layer of something or the outside layer of something? Have a look around you and can you see any surfaces where you are right now? So my computer at the moment is just resting on the surface of my table.

Can you see any surfaces around you? So we could think about the surface of our skin, that's the outside layer, isn't it, of our bodies.

Or we might think about maybe a piece of furniture, like the surface of the sofa is made of fabric.

And another surface that you might have noticed if you are near a window or if you are outside is the surface of a tree trunk and that's known as bark.

Did you find any other surfaces when you were looking around where you are right now? We know that surfaces can be natural and we also know that surfaces can be made by people.

What other surfaces have you noticed? Think for a moment about which are found in nature and which surfaces have been made by people.

So here we've got a natural potato skin and also we've got the surface of floor tiles, which have been made by people.

Lots of different surfaces all around us.

Surfaces can be different shapes, and we can see that the potato skin is a very different shape to the floor tiles.

Here are a few more examples.

So we've got a flat tabletop surface, and then we can also look at the round surface of a football.

Now we live on a planet called Earth, and Earth has different surfaces in different places.

So we could think about grass as being as a surface on Earth.

And we could also think about rock.

Very different types of surfaces, aren't they? Different shapes.

We know that snow can also form a surface on the Earth, so we have a surface of snow.

Can you think of any more surfaces on Earth? And here's a great example of a rough surface on sandpaper.

Surfaces can also be smooth.

It sometimes can be quite tricky to think of some examples of smooth surfaces, maybe a mirror, or these very, very smooth, well polished stone steps.

They definitely feel different when you touch them.

Can you find a smooth surface where you are? Go and have a feel of it and feel how smooth it is, and also go and find a rough surface and have a feel of that too, and compare how the two surfaces feel very different.

Pause the video and go surface hunting.

Let's move on to a check for understanding.

What is a surface? So we've got three different choices.

Is it A: the bottom layer of something? Is it B: the middle layer or the inside of something? Or is it C: the top layer or outside of something? Have you made up your mind? And the answer is C.

Yes, we've talked about surfaces being the outside or the top layer of something.

We've talked about our skin, haven't we? And we've talked about the outside surface of a sofa.

Moving on.

Try this True or False question.

All surfaces are made by people.

Do you think that's true or do you think that's false? And the answer is false.

Let's have a think about why it's false.

Is it because the surfaces in school and at home came from a factory, or is it because bark, skin and orange peel are all natural surfaces? So surfaces are made by people is false, and what's the reason why? So we need to be thinking about natural surfaces, don't we? So the answer in this case is B: bark, skin and orange peel, well, they're not made by people, are they? They're all natural surfaces.

Ready to move on.

Sam and Jacob are trying to decide what is a surface and what is not a surface.

So they're looking very closely at this apple.

Now Sam says, "The peel of an apple is a surface because it is the outside layer." And Jacob says, "The peel of an apple isn't a surface because it isn't flat." Have a think for a moment.

Who do you agree with and why do you agree with them? Pause the video.

Well actually, it's Sam that's correct because surfaces can be any shape.

And Sam saying, "The peel of an apple is a surface because it is the outside layer." And don't forget, we've talked about things like skin and sofas and we've talked about bark on the outside of a tree, and not necessarily all of those things are completely flat.

We've also thought about the surface of a football, haven't we? So not all surfaces are like tabletops and floor tiles.

They're not all completely flat.

We're moving on to the second part of today's lesson, and in this part we're going to be learning about how scientists plan how to answer questions.

So we're going to be thinking like scientists now.

And we know that scientists plan different types of investigations to answer questions.

So we start an investigation with a question.

And in this case, Jun has a question and he's wondering, "Does the type of cup affect how long my hot chocolate will stay warm?" What a great question, Jun.

So Jun definitely wants to work like a scientist and try to find answers.

Now Jun knows that there's different types of investigations.

So he has to choose the right type to be able to answer his question as best as possible.

So in this case, Jun is thinking maybe a comparative test investigation.

And we're going to choose that because these types of tests are often used to compare two or more things.

So comparative tests, that's one of our keywords today.

And I think of comparative, I think of that word compare.

Do you? Can you see? The C-O-M-P-A-R right at the beginning of comparative.

And it's the same letters at the beginning of the word "compare".

And what Jun's doing here is he's comparing two or more things.

He's comparing two or more different types of cups and he wants to know does the type of cup affect how long his hot chocolate drink will stay warm.

So it makes sense to carry out a comparative test, doesn't it? To compare different types of cups.

In this investigation, Jun will compare different cups, and Jun's obviously been into his kitchen cupboard and he's chosen two different types of cups at the moment, a ceramic cup and also a plastic cup.

So Jun is going to be changing the type of cup so that he can compare which one is able to keep his hot chocolate drink warm the longest.

In a comparative test investigation, the thing that is being changed has labels, such as the type of something.

And in this investigation, that's right, isn't it? Because Jun is changing the type of cup.

The labels in this case are ceramic cup and plastic cup.

Now Jun's got to really think about this because he's carrying out a comparative test and he wants to make sure that he's comparing his cups in a really fair way.

So to be able to do that, we change one thing that we are investigating and we measure one thing and we keep everything else the same.

So remember Jun's question, "Does the type of cup affect how long my hot chocolate will stay warm?" So we know the thing that Jun is changing, don't we? He's changing the type of cup and that's the only thing that Jun is changing.

It says we change one thing.

That's the only thing that we are investigating.

Now what else do we need to think about? Oh, it says here that we keep everything else the same.

So some of the things that Jun must try to keep the same are: he's going to use the same amount of hot chocolate in both cups; he's gonna make either has a lid or doesn't have a lid in both cups.

Keep those the same.

And he will also need to make sure that the starting temperature of the hot chocolate is also the same.

So it wouldn't be a very fair comparison, would it, if one of the hot chocolates started at a higher temperature than the other one? These are the things that Jun must make sure that he's keeping the same.

And this is really important when we carry out fair tests and also comparative tests.

Let's think about this a little bit more with our check for understanding.

Now we know that Jun's question is, "Does the type of cup affect how long my hot chocolate will stay warm?" So think about two things that Jun should keep the same in his investigation.

Now we've already thought about some other things, but let's think about anything else.

So would Jun keep the same, the amount of hot chocolate? Would Jun keep the same the place where he does the test? And would Jun keep the same, the type of cup? Have a think about it for five seconds.

Have you got some ideas? And the answers are actually two things here.

So he needs to make sure that there's the same amount of hot chocolate in both cups and he also needs to make sure that he does the test in the same place.

If he does the test in different places, one room might be a bit colder than the other room or one room might have a window open.

So that might affect Jun's results.

So why doesn't Jun need to keep the type of cup the same? Have you remembered? In Jun's comparative test, he's changing one thing, and actually, the type of cup is the thing that he's changing as he's comparing different types of cups.

Have you remembered that? Well done, everyone.

So we're moving on to our practise task and we're thinking about comparative tests.

Now remember, a comparative test is we want to compare two or more things in a fair way.

Her question is, "Does the type of paper affect how far the aeroplane flies?" So here's your task.

First of all, can you make a list of the things that Laura could change in this investigation? So each time Laura makes a paper aeroplane and sends it across the room, what are the different things that Laura might change each time she does that? So that's the first part of the task.

And then the second part of the task is which of these things should Laura change? So look down at your list of all the different things that Laura could change, but go back to actually what Laura wants to find out and which of those things would Laura change? Remember, it's just one thing that Laura's changing in this comparative test investigation.

Pause the video and have a go.

So how did you get on? Lots of thinking to do.

Laura's asking, "Does the type of paper affect how far the aeroplane flies?" So what are all the different things that Laura might change? Your answers might include: Laura might have used a different type of paper each time.

Laura might use a different size of paper.

That's a good idea.

Laura might change the way that she folds the paper.

There's different ways of making paper aeroplanes.

Laura might change the way the person throws the aeroplane.

So overarm, underarm, lots of different ways of throwing.

Now let's think about what's the one thing that Laura will change? Now remember she's asking "Does the type of paper affect how far the aeroplane flies?" So what's the thing that Laura's changing? The clue is in the question.

Laura is going to change the type of paper.

Go back to the question, "Does the type of paper.

." There you go.

That's the thing that Laura is going to change.

Remember, everything else must be kept the same each time an aeroplane is tested to compare it in a fair way.

Well done, everyone.

Moving on.

Here we are at the third and final part of today's lesson, and now we're going to be thinking about how do surfaces affect how things move? Well, we know what surfaces are and we're going to start thinking about how things can move over surfaces.

So for example, a toy car can roll over a surface.

An animal, such as this stick insect here, can walk over different surfaces.

And also we might think of a window as a surface.

And we know that water can drip or run over different surfaces.

So we're going to be thinking about do different things move over different surfaces in the same way? And here's a question for you.

Do you walk in the same way over the surface of sand and on the surface of ice? Or would there be any differences in how you would move over these surfaces? Do you think the type of surface affects how things move? Well, I know in the wintertime when it's cold and frosty and icy and I'm trying to walk on ice, it's a very smooth and slippery surface.

So I walk in a very careful and cautious way so that I don't slip over and end up on the floor.

But I know that if I've been to the beach and I'm trying to walk across the sand, it's quite difficult isn't it? To walk over sand.

You've really got to use your muscles and your power in your legs to walk over sand because these are really quite different surfaces.

So I think the type of surface does affect how things can move, do you? Objects move differently over different surfaces.

Here we have a smooth tarmac road.

And also if we compare that to a rough stone track, I think these surfaces are very different to each other.

Some surfaces are easy to move over, but others can be rather difficult to move over.

Now we can use a comparative test investigation to compare how things move on different surfaces.

We can change the type of surface.

So we could maybe have tarmac, we could have stone, we could have sand, we could have ice.

So we're using different labels to describe the thing that we are going to be changing each time.

Let's have a quick check for understanding.

True or false? A comparative test investigation could be used to compare how objects move over different surfaces.

Do you think that's true or false? Yes, it's true, isn't it? So we've been talking about comparative test investigations.

So what would be our reason for this question being true? Do we think it's because a comparative test investigation can be used to group things? Or do you think it's because it can be used to compare two or more things? And the answer is B, because we've been thinking about comparing different surfaces, haven't we? So a comparative test would be a really good choice for this investigation.

Izzy wants to carry out a comparative test investigation.

She wants to compare different types of surfaces and find out how surfaces affect how a marble moves.

Ooh, that's a really interesting investigation.

So we're not thinking about how we move over surfaces anymore.

We're going to get a little marble and maybe we're gonna roll it across different surfaces.

I wonder if the marble rolls across different surfaces in the same way.

Now we know that scientists make decisions about how to set up and carry out their investigations.

So Izzy's being a scientist.

She needs to make decisions about how to set up and carry out an investigation, just like scientists do when they're carrying out their own investigations.

First of all, scientists need to decide what question they want to answer.

We've talked about that already, haven't we? And we know that at the start of an investigation, we have our question.

Izzy is thinking like a scientist about what question she could ask.

What could her question be? Do you have any ideas? Do you remember? She's got this idea that she has the marble and she's gonna roll it across different surfaces, maybe.

What could Izzy's question be? Now here's Izzy's question.

"Does the type of surface a marble rolls on affect how far the marble moves?" Great question, Izzy.

Did you have a different question? Pause the video and share with a partner what your question was.

Let's try this check for understanding.

Which of these questions about surfaces could you answer using a comparative test investigation? Is it A: How far can you push a brick across different surfaces? Is it B: Which is your favourite surface? Or is it C: How are different surfaces made? And the answer is A.

If you got that one, very well done.

Did you remember that we use comparative tests to compare two or more things? Onto your final practise task now.

And your task today is, you are going to plan Izzy's comparative test investigation.

You might use a ramp or you might use a tube.

You are gonna have to launch the marble somehow.

You might just push the marble.

Or you might have different ideas.

You will need a metre ruler or a tape measure maybe.

A marble, definitely need a marble.

And you need to find a range of different surfaces to test the marble as it rolls across.

Okay? So have a think about it.

And what I'd like you to do is draw a label diagram.

So think about the equipment that you're going to need and draw a picture of how you're going to set up your test.

And this is going to be a scientific diagram.

So I want you to label what all the different parts of it are.

And can you use this diagram to show or to describe to somebody how you would set up your investigation and what you would do? Now you're not actually going to carry out the investigation today.

Remember, today's lesson is about planning.

Planning to compare how a marble rolls across different surfaces.

Pause the video and start thinking and planning.

Now the next part to your task is to make a list of all the thing that you could change in this comparative test investigation.

So each time you roll the marble, I want you to think, is there anything that you could do differently each time? And these are the things that you could possibly change.

Make a list.

There's lots of different things that you could change.

Now remember, with a comparative test, you need to compare the surfaces in a fair way.

You can only change one of the things in your list.

So have a look down the list of things that you've made.

And first of all, which thing will you change? So think about the question and think about what you're trying to find out in your investigation.

Pause the video and keep planning.

So let's take a look at some ideas.

Does the type of surface a marble rolls on affect how far a marble moves? If you look in this diagram, we start off with a book with one end of a plank of wood raised up to make a ramp.

And we're going to put our marble at the very top of the plank of wood and we will leave go so that the marble rolls down the ramp.

And when it gets to the tabletop or to the carpet, we will put a number of rulers or a tape measure on the floor and we will measure how far the marble rolls across the surface.

Now in this case, we've got a strip of carpet taped to the floor.

And each time we roll the marble from the top of the ramp, we will put a different surface at the bottom of the ramp.

So we need to think about different surfaces that we can use.

Are your ideas and your diagrams similar to this? Or did you have a different way of carrying out this investigation? Now moving on to our list.

So there's lots of different things that we might change when we carry out this comparative test investigation.

You might have thought of some of these things or you might have some other ideas.

So each time we roll the marble, we could change, if we wanted to, the height of the ramp.

What else might we change? Oh, we might change the length of the ramp.

So remember we are using a plank of wood.

We might use a shorter plank or a longer plank each time.

Oh, we might change the starting position of the marble.

So in our investigation, we've put the marble at the very top of the ramp, but we might decide to roll it maybe from halfway down the ramp.

So we could change that each time.

We could change the type of surface at the bottom of the ramp.

So in this example, we might have carpet and then we might change it to some kitchen tiles, or we might change it to a rolled out sleeping bag.

Or we might change it to taking the ramp outside and working on the pavement.

Oh, another thing that we could change, yeah, are you going to just leave go of your marble and let it roll? Or are you gonna push it gently? Or you could change that and you could push it a bit harder each time so you could change the amount of push you give to the marble.

Did you think of other things that you could change too? Now finally, we're going to think of just the one thing that we will change.

So thinking about Izzy's question, the thing that we will change is the type of surface.

Yes, 'cause Izzy wants to know, "Does the type of surface affect how far the marble rolls?" So Izzy's saying, "I will change the type of surface at the bottom of the ramp.

To compare the surfaces in a fair way, I will keep everything else the same." So let's move on to our summary of today's lesson.

Lots of learning going on today.

We know that the surface is the top layer or the outside of something.

Do you remember that one? And we also know that things move differently on different surfaces.

Now, we've been working like a scientist today, haven't we? We know that scientists can plan investigations to compare two or more things.

And in today's lesson, we've been learning about a comparative test.

And that's one way of being able to compare things in a fair way.

And we have to make sure that only one thing should be changed each time measurements are made.

Fantastic work, scientists.

I'm really looking forward to carrying out our comparative test investigations and hopefully being able to find answers to our scientific question.

I'll see you next time.