S. I. Ramanujan was a self-taught prodigy from India. His introduction to the world of formal mathematics and subsequent fame arose from his correspondence and collaboration with the renowned British mathematician Godfrey Harold Hardy . In his short but prolific career Ramanujan made several important contributions to the field of number theory, an area of pure mathematics that deals with the properties of and patterns among ordinary numbers. Three quarters of a century after his death, mathematicians still work on his papers, attempting to provide logical proofs for results he apparently arrived at intuitively. Many of his theorems are now finding practical applications in areas as diverse as polymer chemistry and computer science, subjects virtually unknown during his own times.

Srinivasa Iyengar Ramanujan, born on December 22, 1887, was the eldest son of K. Srinivasa Iyengar and Komalatammal. He was born in his mother's parental home of Erode and raised in...