A logical place to start for Americans is Mu Alpha Theta, the National Math Honor Society. From there, you can join many team-based competitions such as the Math League, Math-O-Vision, Moody's Mega Math Challenge, MATHCOUNTS, etc. For a more individual challenge, there is USA Mathematical Talent Search (USAMTS), which offers one month for solutions to be submitted, but offers the most extremely challenging problems.
Chat with our AI personalities