Science, Math, Recreations, Competitions - Australian Primary Schools Mathematical Olympiads Inc.. Open to primary schools in Australia, New Zealand and surrounding countries.
Science, Math, Recreations, Competitions - USA Mathematical Talent Search (USAMTS). A free mathematics competition available to all high school students in the United States.
Science, Math, Recreations, Competitions - MATHmodels. A online team competition where students compete to solve real-life problems using mathematical modeling.
Science, Math, Recreations, Competitions - The Mandelbrot Competition. Includes introduction to contest, news, memos, resources and on-line registration.
Science, Math, Recreations, Competitions - Math League. Specializes in math contests, books, and computer software designed for students from the 4th grade through high school.