John William Wrench, Jr. (October 13, 1911 – February 27, 2009) was an American mathematician who worked primarily in numerical analysis.
[3] Wrench started his career teaching at George Washington University, but switched to doing research for the United States Navy during World War II.
[3] During the period 1945–1956 Wrench and Levi B. Smith used a desk calculator to produce more and more digits of π, ending with 1160 places.
[4] In 1961, Wrench and Daniel Shanks used an IBM 7090 computer to calculate π to 100,000 digits.
[5] Harry Polachek had a printout of the 100,000 digits specially bound, inscribed in gold letters, and donated to the Smithsonian Institution.