Chinese teen who aces International Mathematical Olympiad twice used to cry over scoring average in English

Seven of the 666 contestants from 117 countries and territories reached full marks, according to the official IMO results, which show Deng taking 7 out of 7 on all six problems. China finished first with 232 points, 25 clear of the U.S., and all six of its contestants won gold, Shanghai Daily reported.

The U.S. team placed second with four golds, and its own perfect scores went to Alexander Wang and Liam Reddy, according to the Mathematical Association of America, which organized the American team.

Achieving perfect scores at separate olympiads like Dang is rare in China. Jimu News reported in 2024 that Shi Haojia had become only the fourth Chinese contestant to manage it, after Luo Wei, Fu Yunhao and Wei Dongyi. Wei, who scored 42 in both 2008 and 2009, is now an assistant professor at Peking University and a minor celebrity in China.

But Dang has experienced not only winner glory in his student life. He did not do so well in languages in secondary school, and used to cry over it.

At the opening ceremony of Huayu Private Middle School in Shanghai on Aug. 31, 2025 after winning the IMO gold that year, Deng told students about scoring 89 out of 100 on a seventh-grade English exam, exactly the class average, The Paper reported. The class monitor scored 99, and Deng heard that the teacher had deducted a point deliberately to stop the boy getting arrogant.

He cried on the way home. It was the first time he grasped how far apart two people’s aptitudes could sit, he said.

“Even if I studied English 24 hours a day, I couldn’t score 99 or 100,” he told them.

Chinese was Dang’s other weak subject. He listened closely in every lesson, took notes and memorized them exhaustively before exams, and in one major test still finished a point below the class average, according to The Paper‘s account of the speech. The boy sitting in front of him, who slept through Chinese lessons and did his homework carelessly, came first in the class.

Everyone has their own path and pace, Deng told the assembly. Accept the weaknesses, find the thing you love and go deep into it, he added.

His math talent showed up early. He could recall every phone number stored in his parents’ phones, and at a little over three he worked out that any three-digit number made of three identical or three consecutive digits is divisible by three.

Once Huayu identified the ability, it let him study alone in the library during self-study periods and lessons outside the entrance-exam subjects, and waived some of his daily homework, Sun Jiayi, an English teacher who was his homeroom teacher for four years, told The Paper.

Liu Zifan, a middle school classmate, told Jiefang Daily that Deng could drop at will into the long, meditative concentration that hard mathematics demands.

In eighth grade he won the Weiming Award, the top prize at Peking University’s mathematics and technology summer camp for secondary students, and a first prize at the fifth National Liu Hui Cup. On Nov. 3, 2024 he placed fifth globally in the combinatorics and probability track of the Alibaba Global Mathematics Competition, the first pre-university student to win a medal in that event, The Paper reported.

That December, by then at Shanghai High School, he took a perfect score and first place at the 40th Chinese Mathematical Olympiad, which carried him into the national training squad. He came through the second round of selection the following March as the only 10th grader on the team, the first Shanghai student in roughly a decade to reach it at that age, Xinmin Evening News reported.

What separates Deng is less the raw ability than the composure, Wang Guangting, Shanghai High School’s mathematics competition coach, said in remarks carried by Jiefang Daily. When Deng meets a problem he cannot see through, he regulates himself and stays level, which is the temperament top contestants need.

His first IMO, in Queensland, Australia in 2025, ended with the mathematician Terence Tao placing the gold medal around his neck. Deng, who calls Tao his idol, said the moment felt like a dream.

That gold was Shanghai High School’s 18th since 2000, the most of any Chinese school of its kind, Jiefang Daily reported. The school hosted this year’s competition, the first IMO staged by a secondary school since the contest began in 1959, and Deng took the contestants’ oath at the July 14 opening ceremony alongside Swiss contestant Hongjia Meng.

The Chinese Mathematical Olympiad result had already earned him guaranteed admission to university with his pick of major. He passed over computer science and took mathematics.