Ruby Wizardry: An Introduction to Programming for Kids (2014)
Chapter 1. What This Book’s About
Chapter 2. The King and His String
Chapter 4. Staying in the Loop
Chapter 5. Array of Sunshine and Hash on the Range
Chapter 6. The (Chunky) Bacon to Ruby's Hash
Chapter 7. The Magic of Methods and Blocks
Chapter 8. Everything Is an Object (Almost)
Chapter 9. Inheriting the Magic of Ruby
Chapter 10. A Horse of a Different Color
Chapter 11. Second Time's the Charm
Chapter 12. Reading, Writing, and Ruby Magic
Chapter 13. Follow the WEBrick Road
Appendix A. Installing Ruby on Mac and Linux