This is going to sound like nonsense, but the best books that really teach how to think, how to handle complex thoughts and logic, and how to reason multiple steps in advance, and expand that into all the possibilities and still resolve all of that mess into a logical course of action... this process is documented, in story narrative form over and over again in literature. This is how a novel gets nominated for a Nobel Literature award: they depict a situation, typically a dire tragedy, and the individuals facing that situation and how they logically navigate to success. The characters typically begin without the critical thought capacity to succeed in their situation, and the novel is the story of their piece-wise transformation into the critically aware individual operating with reasoning multiple steps ahead of themselves. These novels are not math, are not anything technical, yet they teach their readers a critical skill that math and anything technical requires to master: critical thinking in an unknown space where one needs to make predictions with unknown information, and how to manage that. It's literally a literature "formula".