This third volume in a collection of three (so far) books on Scratch programming focuses on an interesting, powerful, and important technique from computer science called recursion. A recursive program is one which "calls itself”. In Scratch, this means using a block for the script within the very script that defines the block. Recursion makes solving many problems easier, and also allows one to do some things that would be very difficult to do without it, such as drawing intricate fractals. We hope you find the projects in this book interesting, illuminating, and, most of all, fun! And, that the projects inspire you to go on to further study of topics in computer science.
All three levels of Discovering Computer Science & Programming through Scratch were written using both the CSTA (Computer Science Teachers Association) K-12 Computer Science Standards and the ISTE (International Society for Technology in Education) Standards for Students as guidance.
Support for this guide is provided by the 4-H Computing Connections (CS4H) project funded by the University of Illinois Extension and Outreach Initiative and also by the Department of Energy and the Department of Homeland Security under Award Number DE-OE 0000780.
Note: only Level 1 has both Youth and Facilitator Guides; Levels 2 and 3 only have one book per level. The books are designed for the youth, and they include instructions for the facilitator.