Math lovers celebrate March 14 (or "3-14") as Pi Day.
The Greek letter pi represents the mathematical constant that equals a circle's circumference divided by its diameter. The world's most famous irrational number is usually shortened to 3.14 — but not for Marc Umile.
In January, the 40-year-old from Upper Darby, Pa., became the North American record-holder for memorizing pi: He made it to the 12,887th digit.
Umile says he has always been fascinated with human memory.
"For anybody who wants to know how good their memory is, pi is the ultimate test of finding that out," Umile tells Robert Siegel.
A love of music helped Umile memorize the digits of pi. He says he separated the numbers into clusters of 2, 4 and 6, and he also recorded himself reciting pi, and listened to it repeatedly.