An Introduction to 
         Programming with Scratch 
                        Ronald Bourret 
                    http://www.rpbourret.com/scratch 
        
        
        
       Table of Contents 
       Introduction .................................................................................................................................3 
       Chapter 1: Movement and Loops ................................................................................................5 
       Chapter 2: Conditional Actions and Keyboard Commands ........................................................9 
       Chapter 3: Messages .................................................................................................................13 
       Chapter 4: Animation ................................................................................................................15 
       Chapter 5: Practice, practice, practice! .....................................................................................21 
       Chapter 6: Variables .................................................................................................................23 
       Chapter 7: Algorithms...............................................................................................................29 
       Chapter 8: Program Structure ...................................................................................................33 
       Chapter 9: Advanced Programs ................................................................................................41 
       Chapter 10: Project ...................................................................................................................43 
        
        
                    
         Scratch 
         This class introduces programming using the Scratch programming language. The Scratch programming 
         language and environment are a project of the Lifelong Kindergarten Group at the MIT Media Lab. 
         They are available free of charge. 
         You can find Scratch at: 
                 http://scratch.mit.edu 
         License 
         This document is available under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 
         International (CC BY-NC-SA 4.0) license. Under this license, you may: 
                Share — copy and redistribute the material in any medium or format 
                Adapt — remix, transform, and build upon the material 
         Under the following terms: 
                Attribution — You must give appropriate credit, provide a link to the license, and indicate if 
                 changes were made. You may do so in any reasonable manner, but not in any way that suggests 
                 the licensor endorses you or your use. 
                NonCommercial — You may not use the material for commercial purposes. 
                ShareAlike — If you remix, transform, or build upon the material, you must distribute your 
                 contributions under the same license as the original. 
         For a human-readable summary of this license, see: 
                 http://creativecommons.org/licenses/by-nc-sa/4.0/ 
         For the complete license, see: 
                 http://creativecommons.org/licenses/by-nc-sa/4.0/legalcode 
                                          
                                                                 2 
          
                 Introduction 
                 This tutorial will introduce you to programming using Scratch from MIT. 
                 Create a Scratch Account 
                 Before you start programming, you will need to create a Scratch account. 
                 1.  Go to scratch.mit.edu. 
                 2.  Click Join Scratch. 
                 3.  Enter the requested information. (Use your real birth month and year. Do not use your school email 
                     address, as it cannot receive email from Scratch.) 
                 Scratch Editor 
                 The Scratch editor has three main parts: 
                    Stage: Where your program runs. 
                    Sprite list: A list of the sprites (objects) in your program. 
                    Script editor / costume editor: Where you edit your programs or your sprite’s pictures. 
                 When the Scripts tab is chosen, the script editor is shown (outlined in red): 
                  
                 The script editor has three main parts: 
                    Script area: Where you build scripts. 
                    Block menu: Where you choose the category of blocks (programming statements) to use. 
                    Block palette: Where you choose the block to use. 
                                                   
                                                                         3 
                  
    When the Costumes tab is chosen, the costume editor is shown (outlined in red): 
     
                 
                         4