155 Pi Digits Recited From Memory - How Many Do You Know? | Video

National Science Foundation (NSF) mathematician Tom Russell recites a long string of the irrational number. Several NSF Program Staff members had a go at the number from memory as well. The record holder, China's Lu Chao, recited 67,890 according to the Guiness Book of World Records. Pi, Anyone? The Secret to Memorizing Tens of Thousands of Digits

credit : NSF