1 – An Introduction to Scratch

• Understand what a Graphical User Interface is (GUI).
• Understand how to use Scratch Blocks to create a sequence of instructions.
• Investigate arithmetic operators and loops.
• Understand how to output text.

Scratch is a programming language that can be used to make small programs and games. Above is the Graphical User Interface (GUI) for Scratch. A GUI is how the a user interacts with software.

• The Scratch GUI is split into 4 sections
• These are listed below:

• The key areas are:
  1. The Blocks Palette
  2. The Scripts Area
  3. The Stage
  4. The Sprite List

If you’ve used Scratch before and already have an account, then you can skip this section.

• Goto THIS LINK to the Scratch website
• Click on the Join Scratch button in the menu bar.

• Fill in the details required. Be sure to pick a username and password you will remember.
• You should use your school email address when you register, it looks like this: firstname.lastname@carres.uk
• Once you are logged in, click on the Create button in the menu bar.

• Now we can name our file. Call it Practice Scripts.

• Scratch works by dragging blocks of code from the blocks palate into the script area. These blocks then can be stacked to create scripts.
• Let’s make a simple Script. From the Blocks Palate, choose Events.

• Now, click and drag the following block on to the Scripts Area.

• Next choose the Looks scripts from the menu.
• Click and drag the say Hello! for 2 secs block and snap it to the When flag clicked block.

• To run our Scratch script, you just need to click on the Green Flag in the Stage area.

• Now let’s try something a little more complicated.
• Delete your current script by dragging it back to the Blocks Palette.
• We’re going to make the cat grow. You’ll need to search through the Blocks Palette to find the appropriate blocks, and build the script as it’s shown below.
• Now click on the Green Flag in the Stage area to run your code.

• After you have completed the code in Scratch as shown above, try changing what the cat says and how long it says it for.
• Upload your work to the Teams assignment, make sure you screenshot your code and the play screen on the right.

• Try to change the script so that after the cat has grown, it says “I’m Shrinking!” and then returns to it’s regular size.
• HINT: You can use negative numbers in Scratch

• To get level 3, you need to make the cat move around in a large circle.
• You’ll probably want to look into using a loop to achieve this.