The Math is Cool Eligibility Rules
Math is Cool will follow the Math Counts school and student eligibility rules. An excerpt from the Math Counts Handbook appears below.
A school is defined as the educational institution, registered with the state, that graduates or promotes students from one grade to the next. Only schools or organizations that meet this definition may register teams for Math is Cool competitions. Further, only students whose permanent record is at the school for may participate on the school team.
Anyone can register to participate as an Individual.
--- From the MathCounts Handbook ---
School Definitions: Academic centers or enrichment programs that do not function as students' official school of record are not eligible to register. If it is unclear whether an educational institution is considered a school, please contact your local Department of Education for specific criteria governing your state.
School Enrollment Status: A student may compete only for his or her official school of record. A student's school of record is the student's base or main school. A student taking limited course work at a second school or educational center may not register or compete for that second school or center, even if the student is not competing for his or her school of record. MATHCOUNTS registration is not determined by where a student takes his or her math course. If there is any doubt about a student's school of record, the local or state coordinator must be contacted for a decision before registering.
Rules for 4-8th grade are here
Rules for High School are here