I've recently decided to start preparing for uni, so I figured I need to learn logic and some number theory. I picked up Burton's Elementary Number Theory and wasn't quite comfortable with it, seemed very dry throwing out expressions which I couldn't understand since I'm in still in high school.
Could you recommend me any books on subject which are written in a more approachable manner to a highschooler? I need basics: arithmetic, primes, divisibility, Diophantine, some Fermat maybe.
I also plan on taking some logic. Looking through Tarski's book a little it seemed broad, with not enough emphasis on mathematics. I need some recommendations on that one too. Thank you in advance :)