The 'galacticos', or star players, of Real Madrid have something in common beyond football skill. Their shirts sport prime numbers. Carlos wears number three, Zidane five and Raul seven and, when David Beckham arrived, the first prime number available was 23.
The 'galacticos' are the building blocks of their team just as their numbers are building blocks, or atoms, of maths, according to celebrity mathematician Professor Marcus du Sautoy, an avid soccerplayer who wears number 17.
Professor du Sautoy, 40, who hosts the popular BBC television show Mind Games, has been in Hong Kong over the past week to enthuse students and English Schools Foundation teachers about the beauty of the subject.
At the weekend, he entertained students in the South East Asia Mathematics Competition, held at Hong Kong International School and won by King George V School, with an explanation of the mathematical significance of Beckham's number. And Beckham, he said afterwards, might not be able to help his six-year-old son do his maths homework, but bending a ball into a net demanded an intuitive knowledge of the subject.
His visit to Hong Kong followed a mainland tour.
Professor du Sautoy spends half his working time evangelising about the subject, with funding from the Engineering and Physical Sciences Research Council, and the rest pursuing his own research at Oxford University. He is writing a book that explores symmetry in maths and nature, which will follow on from his best-seller, The Music of Prime Numbers.