MathGrade.com

Math Forum: Discrete Math Problem of the Week
Past problems and solutions, student Recognition.
mathforum.org/

Math Forum: Algebra Problem of the Week
A weekly interactive project for algebra on the Internet. Challenging problems are posted and solutions appear on the Web.
mathforum.org/

Math Forum: Elementary Problem of the Week
A weekly interactive project for elementary school mathematics. Past problems, solutions, and student Recognition.
mathforum.org/

Kiran Kedlaya's Math Problem Directory
Sources of information about mathematical problem-solving. Focusing on long-answer type problems found on Olympiad-type contests or in problem sections of math journals.
www.unl.edu/

Weekly Math Problem USNA
Problems from the United States Naval Academy, also includes archives and solutions.
www.usna.edu/

Math Forum: Geometry Problem of the Week
Past archive and solutions. Receive help from mentor.
mathforum.org/

USSR Math Olympiad, 1961-1986
Problems without solutions.
members.tripod.com/

Olympiad Math Madness
Jeffrey Lockshin's collection of mathematical problems, invented for mathematical olympiads all over the world.
www.geocities.com/

Math Olympiads
Collection of problem sets from International and National Mathematics Olympiads.
cage.rug.ac.be/

USA, International and Asian Pacific Math Competitions Archive
Problems for the US Mathematical Olympiad (1989-2003), International Mathematical Olympiad (1986-2003), Asian Pacific Mathematical Olympiad, and the Team Selection Test.
www.unl.edu/