Let's Dance!

Motion

In Scratch, sprite behaviors are a form of program output. Up until now, we’ve only “heard” output in the form of play sound blocks. However, sprites can do much more than sing (or meow).

The programming blocks located in the Motion tab will affect the sprite’s state—its location (i.e., where it is) and/or orientation (i.e., which way it’s facing). Two of the most commonly used of these blocks are the following:

Moving Turning

Two important things to note about these blocks:

  1. The blocks instruct the sprite to move relative to its state where it is before the block is executed. In other words, you can click on the sprite and drag it somewhere, and move [10] steps will still function correctly and move the sprite 10 steps from its present state. The same is true for turn blocks—no matter which direction the sprite is currently facing, turn [15] degrees will still function correctly.
  2. The number of steps or degrees is customizable. The “holes” in the programming blocks, where a selection can be made, are called parameters. Scratch will allow negative parameters in these motion blocks.

Hypothesize what the following will do:

Implement it and test it out. Were you right? What effect does turning a negative number of degrees have on the sprite?

Motion Combinations

Motion blocks can be combined much like Sound blocks. Hypothesize and test what the following sequence of blocks will do:

Extension

Try to figure out the relationship between the blocks on the left and the buttons on the right. These buttons can be helpful to get the characters to face each other.

Blocks Buttons

Sound and motion need not be separate. Sequences of blocks that combine the two (and other types of behaviors) can be created by switching among the tabs and selecting the blocks you wish to combine. The example dance sequence uses four types of blocks:

  • The brown Control block handles the green flag event, so the program knows when to start and what to do once it has started.
  • The magenta Sound blocks output audio drum beats.
  • The blue Motion blocks change the sprite’s location and orientation.
  • The purple Looks blocks change the sprite’s appearance.
    • Each sprite may have multiple ‘costumes’ associated with it. The default ‘Scratch the Cat’ sprite has two—you can view them by clicking on the ‘Costumes’ tab, then you can switch to a particular costume by name or simply choose next costume to alternate between them.

Instructions

Your job is to remix some starter Scratch code to make it a dance all your own! In the Unit 1 activity, Flow Patterns, you explored the basic components that can constructs any algorithm: sequence, selection, and iteration. Your “dance” that you make will be an example of an algorithm built using only sequencing.

  1. Open a new Scratch project.
  2. Recreate the following Scratch starter code in your Scratch project.
  3. Modify the code and remix it into your own dance!
  4. Share your Scratch dance with a classmate. Describe the modifications you made, and give your dance a name.