The Math Open at Andover (MOAA) is an annual mathematics competition for middle school students organized and run entirely by students at Phillips Academy Andover. Founded by Justin Chang ’19 and Andy Xu ’19, the first MOAA invited 130 students from across the world to the Andover, MA campus in October 2018. MOAA 2019 was a similar success, with 28 teams and 146 total competitors. In 2020 and 2021, MOAA was completely virtual, before offering both in-person and virtual options in 2022.