For summer preparation before calculus and physics, several book recommendations were made, including "Fundamentals of Freshman Mathematics" and "Principles of Mathematics" by Allendoerfer/Oakley, which cover pre-calculus topics and introduce calculus concepts. Gelfand's books were noted for their challenging problems and insightful exposition, making them suitable for building a strong mathematical foundation. Linear algebra was also suggested as beneficial for developing mathematical intuition, with David C. Lay's "Linear Algebra and Its Applications" recommended for its accessibility. Additionally, "What Is Mathematics?" by Courant and "No Bullshit Guide to Math and Physics" by Savov were highlighted as engaging options for reinforcing math skills. Overall, these resources aim to strengthen understanding and confidence in mathematics before advancing to higher-level courses.