I receive many questions from parents about their students’ eligibility for MathCounts. MathCounts is the premier middle school math contest, the one all the AoPS kids talk about on the discussion boards. Students are allowed 3 years of eligibility to participate and once you are in high school you are ineligible. Middle school students participate no matter what math course they are studying, even if it is at an advanced level.
Depending on who you talk to, some people argue that younger students who are talented in math are allowed to participate. This may technically be true, but the reality is that MathCounts is very competitive, if not at your local Chapter, then at State or Nationals. Students spend a lot of time preparing for MathCounts. Like a lot a lot.
For some idea of how top students perform, check out a recent MathCounts National Countdown Round. Even if your student can keep up with these kids, I would not enter them in MathCounts before sixth grade. We’ve had students win at Nationals twice, but we’ve never had a middle school student three-peat there. Maybe your student can be the one. Don’t squander their personal best by participating too early.
TL;DR Don’t start your younger student in MathCounts before middle school. Use your 3 years of eligibility in 6th – 8th grades.