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Willem Klein
Dutch mental calculator (1912-1986) · Netherlands · On the map · Academics · Died at 73
Willem Klein, also known as Wim Klein or under his stage names Pascal and Willy Wortel, was a Dutch mental calculator, famous for ability to perform very complicated calculations in his head very fast. On 27 August 1976, he calculated the 73rd root of a 500-digit number in 2 minutes and 43 seconds.
Willem Klein is read about 15 times a day, in 10 languages.
A typical day, 30 days to 13 June 2026
The middle day of the days counted, so one week of news cannot move it. The line under it is the last 60 days, one point a day.
Something wrong?About this person
This feat was recorded by the Guinness Book of Records.
Country
Netherlands
Category
Academics
Type
Academic
Status
Deceased
Dates
Lived 1912 to 1986 · aged 73
