A Competitor Who Coaches.
USAJMO Qualifier 2025 · President, Math Club · Coach, MathCounts
David Liu qualified for the American Invitational Mathematics Examination in seventh grade, and did not qualify in eighth. He was the school winner on the AMC 10 in 2023 and 2024 and on the AMC 12 in 2025, and in March 2025 the Mathematical Association of America wrote to tell him he had qualified for the USA Junior Mathematical Olympiad, the proof-based olympiad above the AIME, which the MAA's letter describes as reached by fewer than one percent of students in its competitions. The same spring his school team answered all thirty questions of the Purple Comet! Math Meet correctly.
The other half of the page is teaching. He is president of his school's math club and coaches a middle school MathCounts team, and he writes the materials for both himself.
In the future, David hopes to study statistics and put it to work on policy questions, and to keep a weekly session running for younger students while he does.
Results
- USA Junior Mathematical Olympiad qualifier, 2025.
- Purple Comet! Math Meet 2025. 30 out of 30; first place, tied, among the 313 teams in the United States High School 1-1200 division, and first in California.
- Purple Comet! Math Meet 2024. 27 out of 30; first in California in the same division.
- American Mathematics Competition 12, school winner, 2025.
- American Mathematics Competition 10, school winner, 2023 and 2024.
- Berkeley Math Tournament, individual round, Distinguished Honor Roll (top 20 percent), 2024 and 2025.
Coaching
Math Club, Crystal Springs Uplands School
President, since October 2025
A weekly training session for the club's members, more than twenty of them. He writes the problem sets himself and leads the discussion, and enters the club's teams in the Berkeley Math Tournament, the Caltech Math Meet and Purple Comet.
Middle school MathCounts team
Coach, since December 2025
He wrote an algebra course and a number theory course for the team and co-leads the weekly sessions from them; more than twenty middle schoolers have come through. Between sessions he records instructional videos and answers questions online.
One week's session, as the students receive it
Number Theory 101 is five pages: a warm-up, divisibility checks, the fundamental theorem of arithmetic, counting and summing divisors, and worked problems from past MathCounts chapter and state rounds, each with a remark on the shortcut a competitor would actually use.