Lajos Pósa (born December 9, 1947 in Budapest) is a Hungarian mathematician working in the topic of combinatorics, and one of the most prominent mathematics educators of Hungary, best known for his mathematics camps for gifted students. He is a winner of the Széchenyi Prize. Paul Erdős's favorite "child", he discovered theorems at the age of 16. Since 2002, he has worked at the Rényi Institute of the Hungarian Academy of Sciences; earlier he was at the Eötvös Loránd University, at the Departments of Mathematical Analysis, Computer Science. Biography He was born in Budapest, Hungary on December 9, 1947. His father was a chemist, his mother a mathematics teacher. He was a child prodigy. While still in elementary school, the educator Rózsa Péter, friend of his mother introduced him to Paul Erdős, who invited him for lunch in a restaurant, and bombarded him with mathematical questions. Pósa finished the problems sooner than his soup, which impressed Erdős, who himself had been a child prodigy, and who supported young talents with much care and competence. That is how Pósa’s first paper was born, co-authored with Erdős (hence his Erdős number is 1). He went to the first special mathematics class of the country at Fazekas Mihály Secondary School from 1962 to 1966, where his classmates included Miklós Laczkovich, László Lovász, , Zsolt Baranyai, István Berkes, Katalin Vesztergombi, Péter Major. He won the first prize on the International Mathematical Olympiad in 1966 (Bulgaria) and second prize in 1965 (Germany). He started his Mathematics studies at ELTE University in 1966, and graduated in 1971. From 1971 to 1982 he worked at the Department of Mathematical Analysis at ELTE University, and he obtained a doctorate in 1983 with his dissertation about Hamiltonian circuits of random graphs. From 1984 to 2002 he worked at the Department of Computer Science at ELTE University, and since 2002 he has been a member of the Rényi Mathematical Institute. Despite his significant results in mathematical research, he stopped research and devoted himself fully to Mathematics Education. Erdős, who preferred him among all his protégés, expressed his regret that Pósa had stopped research with the typical Erdős style phrase "Pósa is dead." Mathematics education He started teaching mathematics very early. He tutored his secondary school classmates, and during his first year at university he started teaching extracurricular courses at his former secondary school. His students at that time included: László