Moving the sprite

To get you started using the Scratch blocks, you will learn how to move and turn the Cat sprite. To do this, you will use an Event block to start a set of instructions and add blocks from the Motion category.

Event and Motion blocks

To start your program, you are going to use the when green flag clicked block from the Events category on the Blocks menu on the left.

When you click the green flag above the top left-hand corner of the Stage, Scratch will run the block connected to the bottom of the when green flag clicked block.

Each block will then run in the order of the sequence they are in, one after another.

You are also going to use the move () steps block from the Motion category.

The move () steps block will move the sprite in the direction the sprite is facing. The value in the block determines how far it moves. In the example above, the number of steps is set at 10. You can change this to any whole number to increase or decrease the length of the move.

Pixels and step length

To understand what distance your sprite will move on the Stage, you need to understand that your screen is made up of a grid of pixels (short for picture element). A pixel is one of the small squares that make up an image on your screen. Pixels vary slightly in size depending on the screen, but typically one pixel-length is less than 0.5mm.

One step is equal to moving along by the length of one pixel. The default of the move () steps block is 10 steps which is 10 pixel-lengths on your screen.

Turn blocks

The Turn blocks change the direction that the sprite is pointing. Scratch measures this in degrees (which split a full rotation up into 360 degrees), clockwise from vertically upwards (12 o’clock). Most sprites start with a direction value of 90, meaning that they are pointing horizontally to the right.

You can use the turn right () degrees block shown below to change the direction value of the sprite the specified amount of degrees clockwise.

The default value for the turn block is 15. This will rotate your sprite 15 degrees in a clockwise direction as shown by the arrow on the block. You can change this value to any other angle you would like the sprite to rotate by.

The turn left () degrees block carries out a similar instruction to the turn right () block, except it will rotate your sprite in an anticlockwise direction.

Your first program!

You are now going to create your first program in Scratch! Following these instructions, being careful that you do this exactly:

1. Drag the when green flag clicked block onto the code area from the Events category of the Blocks menu.
2. Drag the move () steps block from the Motion category of the blocks menu and snap it to the when green flag clicked block.
3. Drag the turn right () degree block to the Code area and snap it to the bottom of the move () steps block.
4. Click on the green flag on the Scratch user interface.

You should see the Cat sprite moving and rotating each time you click on the green flag.

1. Increase the the number in the move () steps block. This will make the sprite move a larger distance in the direction it is facing when you click the green flag.
2. Click the green flag again to see how the change you made affects the movement of the sprite.
3. If you are using the installed version of Scratch, click on File and Save to your computer. Type a suitable file name and click Save. If you are using the online version of Scratch, make sure that you are signed in and change the project name by clicking on the current name (usually “Untitled”) at the top.

The Stage edge

As you move the sprite, it’s possible to have a situation where you would expect that the move that you have programmed would lead to the sprite moving off the Stage. Scratch will stop the whole of the sprite from leaving the Stage and will leave a small part visible.

Task

Use the blocks in this step to move your sprite to each corner of the Stage.

• What top tips would you give to other learners who are creating their first program in Scratch?

Share your thoughts in the comments below.