Lesson video

Hello, everybody.

Welcome to Computing.

My name is Mrs. Franzsen, and it's really great to see you here.

Thank you for joining me in this lesson today.

We are going to be doing some coding today.

Let's get started.

By the end of this lesson, you will be able to adapt a programme to a new context.

Let's look at our keywords for today.

The first word is extension, and extension is an option that adds new features to a Scratch project.

Our next keyword is setup.

The setup is a part of a programme where the starting instructions are given, such as clearing the screen or setting a sprite's position.

In the first part of the lesson, you'll be drawing a picture using the pen tool.

In this lesson, you will create a Scratch drawing project.

This project introduces a new feature of Scratch.

The feature is called an extension.

That's one of our keywords.

And extension makes new blocks available for a Scratch project.

To open the extension menu, look for the purple icon in the very bottom left of the screen.

Select the pen choice in the extension menu.

On my screen here, it's the second choice, with the rainbow coming out of the pen.

The pen extension lets you create programmes that make sprites draw on the screen as they move.

When you select the pen extension, new blocks are displayed.

You can see the new blocks here in my screenshot.

These blocks are pen blocks and are used for drawing.

You can see that they have a pen icon next to the blocks.

Let's do a check here.

What is the name of the Scratch extension used for drawing? Is it A, pencil, B pen, or C, sketch? You can pause the video here to think about your answer.

The answer is B, pen.

Well done if you got that right.

If you hold a pen above a page and then you move it down, it will touch the paper.

When you move the pen, it makes marks on the paper.

Just like the real-life example, the pen down block is used to draw lines.

Once the pen down command is run, the sprite will draw as they move.

You can change the colour of your pen.

The sliders will let you select a specific colour shade.

Let's do a check here.

True or false? The pen down block turns the drawing function off.

Pause the video here to think about your answer.

Welcome back.

The pen down block turns the drawing function off.

The answer was false.

Why? The pen down block makes the sprite draw lines.

Well done if you got that one right.

Alright, we're gonna get ready for a task now.

The first step is to open the project.

The project is called Explore Pen.

The pencil sprite already has movement and pen code.

It will move when the arrow keys on the keyboard pressed.

The first step is to change the pen colour, the second step is to draw a house using the pen tool, and the third step is to test the clear button.

Click on the clear button to use it.

How do you think the clear button works? Look at the code on the clear button and then discuss your ideas with a partner.

I'll be here when you get back.

It's time to go and work on the first task.

Welcome back.

I could see people who were working really hard on trying out the pen tool and testing out the clear button.

Let's see what some people had to say.

Laura said, "I noticed that the clear button was a sprite.

It had the event block, when this sprite is clicked, on it." Thank you, Laura.

Aisha said, "When you click on the clear button sprite, it runs the pen code block, erase all.

That clears all of the pen drawing away." Well done for working on this part of the task.

In the next part of the lesson, we are going to look at creating the setup code for a project.

Your project should start in the same way every time it's run.

This is called the setup.

Remember, setup was one of our keywords.

Blocks can be added to a project to make sure this happens.

What do you think will happen when the green flag is clicked in this project? You can pause the video here to think about your answer.

Welcome back.

Let's see what some other people had to say.

Andeep says, "When the green flag is clicked, the pen colour changes.

Then, the sprite starts drawing." Thank you, Andeep.

And Sofia says, "The setup code gets the programme ready to start drawing." It definitely does.

This Scratch project had no setup code.

Why do you think setup code is important? You could pause the video here and share this question with someone near you or think about it for yourself Without setup code, the lines remain on the screen and the pen starts from wherever it is on the screen.

This can make the drawing project difficult to use.

Let's do a check here.

The part of a programme where the starting instructions are given is called the A, scene, B, setup, or C, stage? Pause the video here to think about your answer.

Welcome back.

The answer is B, the part of a programme where the starting instructions are given is called the setup.

Well done if you got that one right.

What kinds of things do you think you'd need in a drawing programme setup code? This block moves a sprite.

The values of 0 for both x and y means that the sprite moves to the middle of the stage.

This is helpful to get a sprite back to the beginning.

This block, pen up, stops the drawing.

It is useful if you don't want the sprite to draw when it moves.

This block, erase all, it erases all of the lines that have been drawn.

This is useful when cleaning up the page.

Setup code will also need an event block to trigger it.

You can decide where and how your setup code starts.

The green flag is used quite often as a way of setting up or resetting a project.

Let's do a check here.

Which block sets the sprite's start position to the centre of the screen? Is it A, glide 1 seconds to mouse-pointer, B, point in direction 0, or C, go to x: 0, y: 0? Pause the video here to think about your answer.

Welcome back.

The correct answer is C.

Well done if you got that one right.

Okay, it's time for a task now.

I want you to open up the project.

The project is called Create Drawing.

Once the project's open, I want you to add the pen extension, then create a setup code to get the project ready to start drawing.

The setup code will need an event block.

Make the pencil sprite draw.

Change the colour of the pen line, and reset the position.

Then, create a setup code to get the project ready to start drawing.

The setup code will need an event block.

Make the pencil sprite draw.

Change the colour of the pen line, and reset the position of the sprite.

These coding blocks will be able to help you do that.

It's time to go and work on your task, and I'll be here when you get back to see what you've made.

Welcome back.

You worked really hard on that task.

It's time to watch the video to see the steps for task B and watch me create the setup code for a project.

In this task, we are first going to add the pen extension, so we're gonna go down to the bottom left, press on the Extensions button, and add the pen.

So now we can see all of the pen commands.

We are gonna add an event block here.

I'm going to use the flag to make my setup code to get the project ready to start drawing.

So I'm going to need the pen down, set the pen colour, I'm going to need erase all to rub out all the lines.

And then I think also a motion block.

I'm going to use the go to block, and we've learned that if you put 0 in both of these values, it will put this sprite right back to the centre of the screen.

So which order do these blocks go in? Well, you might have to test out a few different combinations.

I'm going to go with erase all first, then move to the centre, set the pen colour, and then put the pen down, ready to draw.

Let's test that out.

I'm going to press the flag.

Now, the drawing commands are working well.

The pan down and change the colour are both working.

When I press the flag to erase, let's see how that works.

I'm going to press the flag.

Now, it did leave a line behind, and that's because the order of my sequence of blocks isn't quite right.

After the lines were erased, the sprite then moved to the middle, which drew the line.

So I'm going to change this around.

I'm going to first of all move the sprite to the middle, then erase the blocks.

That should work better.

Let's test it this time.

There we go.

My setup code is working correctly for my programme.

You worked really hard in your lesson today.

Well done on all that learning.

Let's summarise what we have learned.

In this lesson, an extension was added to Scratch.

The extension was the pen tool.

The pen down block makes the sprite draw and the erase all block clears the drawings made.

A setup section can be added to a programme to reset the sprite's position and clear the screen.

Every time the programme starts, the sprite is in the correct place and the drawing is erased.

Thank you for joining me in this lesson today, and I hope to see you soon.