For a 'strong foundation', you'll want to look at a first-year textbook and make sure your math skills are up to it. Use something with an eraser on it. Old jo

For a 'strong foundation', you'll want to look at a first-year textbook and make sure your math skills are up to it. Use something with an eraser on it. Old joke from Anonymous: "Theoretical physicists aren't very expensive -- they only need a blackboard and an eraser. Compare that to a philosopher -- much the same but without the eraser."