I found Piers Anthony’s novels, such as the Adept series, to be good preteen rationality books. His characters are constantly trying to figure out the world around them, describe their reasoning, make complicated (for preteen) moral decisions, and solve puzzles. I don’t think his books describe specific techniques that are useful, but they do portray “trying to figure out the world using reason” in a very positive light.
I found Piers Anthony’s novels, such as the Adept series, to be good preteen rationality books. His characters are constantly trying to figure out the world around them, describe their reasoning, make complicated (for preteen) moral decisions, and solve puzzles. I don’t think his books describe specific techniques that are useful, but they do portray “trying to figure out the world using reason” in a very positive light.