1. Problem Solving Strategies, chapter 6(number theory), chapter 1(invariance, only number theory problems for now), chapter 3(extreme principle, again only number theory problems), chapter 4(box principle, same), chapter 8(induction, same), chapter 14(further strategies)

2. 104 Number Theory Problems

3. Structures, Examples and Problems in Number Theory

4. Theory of numbers, Adler(for advanced, if already read all of above)

**Warning: Don't try to learn or memorize theorems. It is a common idea for our campers or olympiad guys to think that you have to know lots of theorems to do well in number theory. The reality is just the opposite. At the IMO, you hardly need theorems you don't know already. Rather you need to spend lots of hours thinking about it. That's why you have to do the Problem Solving Strategies book first, so you can learn without learning theories. If you can't solve a problem, learn by staring at the solution. Don't just understand the solution, understand the motivation behind the thinking. And remember, no one expects you to cover all the books here in this camp. We only expect that you will have a good idea about how you can develop your skills in number theory.**

If you have problems understanding something, send me a pm or email.

If even the first book seems hard to you, pm me.

If you don't have a book, see here https://onedrive.live.com/redir?resid=9 ... lder%2cpdf

If you are a beginner and need some basic problems, try option (1) stated above first and then try all the problems in "Basic Number Theory"

If you want lots of IMO level problems, try "Problems in Elementary Number Theory(PEN)"

If you are acquainted with PEN and tried them before and still need problems or other books or papers, contact me.