Gr 5–7—In these math-based mysteries, readers have to solve problems and, based on their answers, they are directed to another page to continue the adventure. Participants are not truly creating their own adventure-there is only one path they can take since the mystery only moves forward when the puzzle has been solved correctly-and it can be difficult for readers to backtrack or figure out where they left off. The explanations for the problems are clearly written. Unfortunately, Puzzles has a major error that makes the book difficult to use: a beginning section of the adventure is missing a prompt to tell readers where to go next. Mazes has two prompts missing, but this is only noticed if readers give the wrong answer. This series is a clever way to interest kids in math, but younger readers may need some guidance.