# Lesson video

In progress...

Hello everybody.

Welcome to your science lessons with me, Miss Roberts.

I am so excited to be with you for this topic.

I love learning about how to be a scientist and that's essentially what this topic is all about.

Now, whenever I do my science learning with my screen, I always have one really important thing and that is Lenny the Lion here.

And he always helps me with my learning and he listens to my star words and he helps me when I forget things as well.

So if you want to go and get your favourite Teddy, you can pause the video and go and do that now.

Okay, so let's see what else you are going to need.

You are going to need a pencil and a pen, a ruler, and also a notebook or something to write on.

Pause the video and go and get your resources now.

Okay, so the first thing we're going to do are our star words and then we're going to learn about variables.

We'll look at what's a fair test is and then we'll think about some investigations and how we can make them a fair test.

Then you'll need to do your learning review at the end.

So if you're new to my science lessons, when we do our star words, we always go, "Star words, star words, star words." And then it's your turn, ready? Star words, star words, star words.

Well done, should we do that one more time just so you get used to it? So it's my turn and then your turn, ready? Star words, star words, star words.

Your turn, star words, star words, star words.

Well done I love how lots of you did the hands like your stars as well.

Each of the star words have an action, so I want you to make sure that you're using your hands in order to do the actions to help you remember the star words.

Let's have a look at our first word.

The first word is change.

Well done.

Then next word is dependent.

I'm just going to make myself a bit bigger.

Dependent.

Well done.

A dependent variable depends on the independent variable.

So let's do that one more time, dependent, your turn.

Well done.

The next word is independent.

Can you hold up one finger? Independent, your turn.

Independent, you turn.

Well done.

Now, independent has one finger as the action because in a scientific investigation we change one thing.

How many things do we change? One thing and it's the independent variable.

Can you say independent? Your turn.

Well done, you are so good at your star words.

Well done team.

The next word is control.

Can you do nice flat hands, like everything is equal? Your turn.

Well done.

The next one is fair test.

Well done, fair test, your turn.

Good job.

And in a scientific investigation, we always make sure it is a fair test.

We'll talk about that more later in the lesson.

The last word is variables.

I want you to make a V with your hands, variables.

So a variable is something you can change.

A variable is something you can change, well done.

Let's do that definition one more time.

A variable is something you can change.

A variable is something you can change.

Well done, give yourself a pat on the back.

I'm so impressed with your learning so far this lesson, you're all excellent scientists.

So like we said in our star words, a variable is something you can change, well done.

Now remember team, when I'm asking or pausing and going like this it's because I want you to say something to your screen.

So if it feels a bit funny, just means you need to shout at your screen a little bit louder.

So a variable is something you can? Can you say it louder? Well done, something you can change.

Now, there are three types of variables.

The first one is the independent variable.

Can you say independent variable? Your turn.

Well done.

And it's the one thing that we change.

It's the one thing that we change, good job.

The next one is the, what star word was this? Do you remember? Well done, it was our dependent variable.

Can you say it again? Dependent variable.

Well done.

Our dependent variable is the thing we observe or measure.

Can you say that with me? The, oh, I haven't got to everybody.

One, two, three.

The dependent variable is the thing we observe or measure because it depends on the independent variable.

The thing that we change that then affects the dependent variable, which is why we need to measure it.

Then everything else that we could change, we need to keep the same and we call these our control variables.

Can you say control variables with the action? Well done.

Control variables we keep the same, well done.

Let's see if you were listening to that first slide.

Which variable is the one that we change? Can you tell your screen? Well done.

I want you to write that down in your notebook.

Which variable is the one we observe or measure? I'll give you a clue.

Can you write it down? Pause the video if you need more time for this.

Lastly, which is the variable that stays the same? I'll give you a clue.

Can you write it down in your notebook? Well done.

Pause the video if you need more time to write those out team.

You could also download the worksheet for all of the things that you need to write down for this lesson, if you want to.

Well done.

The independent variable is the one we change.

The dependent variable we observe or measure, and the control variable stays the same.

Well done, everybody.

Give yourself another pat on the back for your learning so far.

Okay, so now let's look at what a fair test is.

Can you give me your thumbs up for fair test? One, two, three, yeah, fair test.

Now, a fair test is what we need to do every single time we carry out a scientific experiment.

We've said already that variables are something that you can change.

But how many things have we said we change? Tell your screen.

Well done, we only change one thing.

So that means that everything else must stay the same.

I'm going to tell you an example.

If I wanted to see how strong a piece of material was, here is my piece of material and I add weights on top of it.

The one thing I'm changing is the material.

Then my dependent variable is the weight because it depends how many it takes to break the material.

Now there are lots of other things that I could change.

Maybe the weather, if it was windy.

Maybe if it was raining.

Maybe if it was hot or cold, that would change the material.

There are lots and lots of things that would change my experiment.

So I need to make sure that I don't change anything else.

I want to keep it a fair test, so I only change one thing.

What I'd like you to do now is have a look at the screen and all of the things that we've looked at so far are on the screen.

So you've got independent variable, control variable, dependent variable, and fair test.

But the definitions are all jumbled up.

So I'd like you to write down in your notebook, the correct variable, or fair test, with the correct definition.

Pause the video and do that now and then we'll mark our answers.

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

The independent variable is the one thing that you change.

The control variables are the things that you keep the same.

The dependent variable is the thing you observe or measure.

And a fair test is making sure the experiment is fair but only changing one thing.

Good job team, I think I really understand now more about variables and what on earth a fair test is.

So now let's have a look at some examples.

In the first investigation there are two girls and they want to see which shoes make it faster to run 100 metres.

One girl wear sandals.

Nice colourful one you can see on the screen.

And one girl wears trainers.

Is this a fair test? Will this help us to see which shoe is fastest? What do you think? Interesting.

Pause the video, if you want more time.

This is not a fair test because there is more than one thing changing.

If one of the girls is very, very sporty she might be naturally faster than the other girl.

The shoes would not make a difference as to who wins the 100 metre race because that's not fair, they're two different girls.

Maybe one girl is taller.

Maybe one girl is shorter.

Maybe somebody hasn't slept very well.

That would make a difference.

Maybe one of the girls runs into the wind and that would make you slower.

There's lots of things that would affect this investigation.

So it is not a fair test because there is more than one thing changing.

Why is this not a fair test, team? Can you tell your screen? Because there is more than one thing changing, well done.

So have a think, how could we make this a fair test? If we really want to see which shoe is going to make us run 100 metres faster, which, sorry, what can we do to make this a fair test? Interesting.

What we can do is we can just use one of the girls so then, we're not changing the girls.

Then the only thing we're changing is the shoes.

So maybe she runs it once in the sandals and then she runs it once again in the trainers.

That would make it a fair test because, can you tell me why? Because you're only changing one thing.

Then you're only changing the shoes.

The shoes would then be our independent variable.

The shoes would be our independent variable.

What would be our dependent variable? What would we be measuring? What did we say we'd measure? Was it how tall the girl was? Was it how big her feet were? Was it how fast they ran the 100 metres? Well done, that makes it that our dependent variable, because the speed depends on the trainers, which is our independent variable and everything else we need to keep the same.

The weather, the girl, whether it's windy, whether it's hot, what ground she's running on.

You could think of lots of other things that could be our control variables that we need to keep the same.

I'd now like you to write down what our independent variable was, what our dependent variable was and as many control variables that you can think of.

Well done.

So as we've said, the independent variable was the type of shoe.

The dependent variable was the speed of the 100 metre run that we'd measure.

And our control variables were lots of things that you could have thought of.

You could have had much more than I've got on the screen, I just wrote down a few.

Have a listen to the next investigation.

We've got some plants and I want to see if sunlight makes a difference to them growing.

One plant I put in the darkness, one plot I put by the window and I feed it water and lots and lots of fertiliser.

Is that a fair test? Can you tell your screen, yes or no? Well done.

It's not a fair test, but can you tell me why? There are some clues on the screen to help you.

Well done.

One of the plant not only had sunlight, but it also had water and I said I'd give it fertiliser.

Therefore, I'm not making it a fair test because I'm changing more than one thing.

So how could you make this a fair test? What was the one thing I wanted to change? Can you tell your screen? Well done.

I just wanted to change whether it got sunlight or not.

So everything else I need to keep the same.

What I could do is I could use one plant that's the same as the other plant.

So the same type of plant, that would make it a fair test.

Then one I put in the dark and one I put in the sun.

Then I keep everything else the same, that would make it a fair test.

Now, Ooh, let's have a think.

What's the one thing I'm changing here? Can you tell your screen? Well done, whether it gets sunlight or not.

Now, I'm going to give you some time to think, by yourself this time, about what our variables are.

I want you to pause the video and write down what you think our variables are in this investigation.

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

The independent variable was sunlight.

I just chose whether it got sunlight or whether it didn't get sunlight.

Then, the dependent variable was the growth of the plant because this depended on whether it got any sunlight.

Everything else were my control variables.

So whether it got water, the temperature I needed to keep the same, whether I gave them nutrients, whether there were other plants around, I would have had to keep lots and lots of things the same in order to make it a fair test, well done.

Team, I'm going to give you an awesome cheer because you've done so well at talking a lot to your screen about your variables and you've done lots of writing about your variables too.

You're working so hard, I'm so impressed.

So, well done everybody, I hope you've enjoyed learning about variables today.