Buffon

To me, the story about how Zu Chongzhi derived the value of π was an important lesson in itself.

It goes like this: When I first read about this as a Form 1 student,  I was told that Zu did it by the needle-throwing experiment. In short, by throwing a needle of length ℓ on a surface on which parallel lines are drawn 2ℓ units apart for n times, and, when n is very large and in x of those times the needle comes to rest crossing a line, then one could determine the value of π by this formula:

π = n / x

But, like many other stories that I heard from that crooked universe, the above account is not true. The scenario that I described just now is, as I learnt latter, known as the Buffon's needle problem – a question first posed in the 18th century by Georges-Louis Leclerc, Comte de Buffon. Simulations that make use of this strategy to determine the value of π involves the famous Monte Carlo-style method of conducting virtual experiments.

Alas, although we may love to, it has nothing to do with Chinese.

PS. It is not entirely difficult to prove mathematically π = n / x. To me, it actually took less time to prove this than to determine how to use three “9”s to make a “20”.