A company employee in Nagano Prefecture calculated the value of pi to five trillion digits this month using a self-made personal computer, beating the record set by a French engineer who calculated it to about 2.7 trillion digits late last year.

To calculate the ratio of the circumference of a circle to its diameter, to an undetermined number of digits, Shigeru Kondo, a 55- year-old resident of Iida, assembled a computer with 32 terabytes of hard-drive capacity and used an application made by Alexander Yee, a 22-year-old student at a U.S. graduate school.

After Kondo repeated tests via e-mail, he began the computation on May 4, and the work lasted 90 days and about seven hours until it was completed on Aug. 3, including verifications, following difficulties including a power outage. He plans to apply for the Guinness Book of Records.

Read the rest of the story: Man in Nagano computes value of pi to 5 tril. digits.