John Nordell / CSM
A pair of Japanese and US computer whizzes currently holds the record for calculating the most digits of pi – to five trillion decimal places. In 2010, Shigeru Kondo, a Japanese system engineer and Alexander Yee, an American computer science student, eclipsed the previous record of 2.7 trillion places. The pair used a desktop computer with 20 external hard disks that cost about $18,000 to build. It took 90 days to make their calculation.