Late at night, numbers and equations swirl across junior Rachel Chen’s page as she chases a solution that remains just out of reach. The clock ticks past midnight, but she won’t give up. For Chen, this persistence reflects a passion she’s honed through years of self-study, competitions, and late-night problem-solving.

Chen’s interest in math first emerged in elementary school when she began learning programming. Starting with C++, a programming language, she quickly realized that coding required strong math skills. However, elementary school math did not provide the challenge she sought, so she took matters into her own hands.

“I was lucky because we were already studying functions, but I started self-studying math more,” Chen said. “I took online classes for math and had a relative—he’s basically a genius—who helped teach me.”

Chen thus participated in robotics and coding contests, earning a gold rank in the USA Computing Olympiad (USACO) in middle school. However, as her interest in math deepened, she shifted her focus from programming to competitive math.

“Over the years, as I learned more, I realized that I loved math more, so I changed from sequence class, which is coding, to math,” Chen said.

Chen has competed in multiple national math competitions, including the American Mathematics Competition (AMC), the American Invitational Mathematics Examination (AIME) and the USA Junior Mathematical Olympiad (USAJMO).

The AMC is the first round of highly selective contests to identify top young mathematicians. High scorers on the AMC—typically those ranking in the top 2.5%—qualify for the AIME, a rigorous exam that demands problem-solving skills. From there, the best 250 mathematicians advance to the USAJMO/USAMO, an elite proof-based competition that requires students to write full, formal mathematical arguments.

“I started with the AMC, but I didn’t take AMC 8. I just took AMC 10 directly in eighth grade. The first time I took it wasn’t good because I was back in China at that time, and so I was not so good at English—the AMC is an English math competition,” Chen said. “But it was still really fun. Then I studied for a year, especially learning English more, and my results improved.”

By  her sophomore year, she had earned a 132 on the AMC 10, which is more than twice the national average of 64.74 and well above the 123-point threshold that marks the top 2.5% of test-takers.

Additionally, given that the standard deviation for AMC scores hovers around 24 points, Chen was in the top 0.25 percentile of all test takers, outperforming 99.75%. Thus, she qualified for AIME and then advanced to USAJMO.

“That was where my math competition journey [that year] kind of stopped,” Chen said. “It was getting too hard because they put events in calculus, which, at the time, I didn’t even know yet.”

Senior Nate Brown, a fellow AIME competitor and co-president of the math club with Chen, says that Chen’s relentless persistence sets her apart.

“She demonstrates drive,” Brown said. “This year, she got around a 140 on the AMC. And she was disappointed. So then she took the AMC B to get a perfect score, and she did it.”

According to test data from 2024 to 2025, a score of 140 put Chen approximately in the 99.98th percentile. That means that out of 21,222 students for the AMC A, she was among the top three to four students overall based on her original score.

“She’s very calm and focused. During the AIME, I lost track a couple of times, just because it’s a three-hour-long test,” Brown said. “However, I did not observe her looking away from her paper; she was truly head-on, [like a] bullet train.”

Junior Thomas Wei also emphasizes Chen’s devotion to math.

“When I have heard her talk about her competitions in the past, what always stands out to me is how passionate she feels about the problems,” Wei said. “I think that being around her makes other students aspire to achieve a similar level of excellence she does.”

Chen has also competed in the Jane Street Math Prize for Girls, an MIT-hosted competition that takes the top 250 female competitors in the nation based on AMC 10/12 and AIME scores.

“It’s a pretty fun experience. They ask really smart questions,” she said.

These competitions require rigorous preparation, which, for Chen, means hours of practice.

“Math is about practice. Since I’m not that smart, I practice problems. I can say that I have done all the AMC problems since 2000,” Chen said. “Recently, I’ve been working on USAJMO and USAMO problems as well.”

Additionally, she spends at least an hour each weekday solving math problems; on weekends, she studies even more.

“I study for five hours each on Saturday and Sunday because I have more time during the weekends,” Chen said. “That’s about ten hours total [on weekends].”

Chen often stays until 2 or 3 a.m. to keep up with her studies, mainly because her online math classes—taught in different time zones—don’t begin until midnight.

“When the class ends, it’s already 2 a.m.,” Chen said. “Then you have to shower off, maybe pack up your bag for tomorrow, and then it’s 3 a.m.”

Chen talks to friends and walks to cope with the pressure of high-stakes math competitions. However, she says that frustrations are just a natural part of math.

“Difficulties are definitely things you will meet every time you face old AMC problems before the 2000s. They are very challenging,” Chen said. “I once spent an hour and a half on a single AIME question and got it wrong. I ended up smashing my computer.”

Despite the difficulties, Chen looks forward to every math competition because of the challenging questions.

“Before tests, I like to guess if there will be more geometry or algebra or sequences or probability or number theory,” Chen said.  “I look forward to weird questions that I would not even imagine, so it’s very exciting to see new problems.”

Though she enjoys the variety, Chen admits that geometry has a special place in her heart.

“I wasn’t born loving geometry; the more I practiced, the more geometry became attractive. The thing with geometry is that it’s not only about numbers. You also get graphs,” she said. “The graphs sometimes change [due to] points moving. Circles are the best—they have moving parts because everything’s changing.”

Chen also credits peers like Nate Brown and Thomas Wei for inspiring her and helping her improve.

“Nate Brown is very smart, and Thomas Wei is good at calculus and physics. At first, I was afraid of Nate—he’s older, super tall and smart. But I respect him very much,” Chen said. “Every time I have math questions that I want to discuss or don’t know, I ask Nate and get smart solutions.”

Despite the demanding schedule, she encourages other students to give math competitions—and math in general—a try.

“Just try the AMC. I recommended it to some of my friends, and they realized it was not hard. The AMC does not really require knowledge [as much as it requires] attention and focus,” Chen said. “If you need help [for math], you can ask me anytime. Even if I look insane from doing math for so long, I promise I’m a friendly person.”