The AMC competitions are the leading math competition for middle and high school students in the United States. Students who do well on the AMC-10 or AMC-12 are invited to take further contests (culminating in the International Math Olympiad). Eligibility is based on grade and age:
Students can take any subset of the exams for which they are eligible, with the exceptions that they cannot take both the 10A and 12A, and cannot take both the 10B and 12B. So, for example, a student in grade 8 or lower could take 10A + 12B + 8 if they wanted.
I will administer these competitions at Brown University for middle and high school students in the area. Links to sign up are provided below:
The deadlines for students to sign up are Nov 1 for the AMC-10/12 and Jan 9 for the AMC-8.