This book offers a simple, entertaining introduction to economics, and it focuses on the area we are usually most aware of: money and inflation—the reasons things are always increasing in price! "Uncle Eric" writes his "letters" in a clear and interesting way, adding fascinating historical comments throughout—quite engaging for the early high school student! He offers just enough economic theory to prod thinking without overloading kids' brains.
The book includes an annotated bibliography with suggestions for where to go next to learn more about economics; a complete study guide by Jane Williams is available; and additional books can help round out the topic of economics. Bluestocking Press recommends Penny Candy and the Bluestocking Guide along with Economics: A Free Market Reader and Capitalism for Kids to comprise a one-semester high school level economics course. If you wish to go further, consider following this up with Maybury's The Money Mystery and The Clipper Ship Strategy.
We would also strongly recommend adding the book Economics in One Lesson to your reading list, as it is a much more thorough introction to free market economics. If you have to choose just one book on the topic, that should be the one.