Wim Klein

Also known as Willem or William Klein and performed under several stage names, including Pascal, Moos Optel and Ali Ben Achmed.

Born 4 December 1912 in Amsterdam. Died 1 August 1986 (murdered in his Amsterdam apartment).

Employed by the Mathematisch Centrum, Amsterdam (1952-1956) and by CERN, Geneva (1958-1976).

Is one of the very best all-round mental calculators.

Claimed numerous "world records". Among them was the multiplication of two 40-digit numbers in 23 minutes. Klein's answer was incorrect - 13 of the 80 digits in the answer were wrong - but was more accurate than the previous best set in c1850 by Zacharias Dase, who erred in 27 digits.

 

Wim_Klein_1.JPG (16506 bytes)     Wim_Klein_2.JPG (19502 bytes)          wim_Klein_4.JPG (235071 bytes)     Wim_Klein_5.JPG (56088 bytes)

Wim_Klein_6.JPG (87838 bytes)     Aitken_and_Klein.JPG (66939 bytes)     Klein_c1950.jpg (10973 bytes)     Klein_Mathematisch_Centrum.JPG (219045 bytes)     Klein_as_Pascal.jpg (11451 bytes)      wim_klein_a1.jpg (5635 bytes)     wim_klein_a2_1974.jpg (19947 bytes)

wim_klein_a3_1983.jpg (187948 bytes)     wim_klein_a4_1976.jpg (36648 bytes)     wim_klein_a6.jpg (91843 bytes)     wim_klein_a7_1986.jpg (33463 bytes)     Wim_Klein_and_Bobby.jpg (37639 bytes)

 

 

 

         

 

Calculations Performed by Wim Klein

 

 

References/Links

1.  A Medico-Psychological Account, Followed by a Demonstration of a Case of Supernormal Aptitude
Proceedings of the Second International Congress on Orthopedagogics, 1949
Berthold Stokvis PDF

2.  World record root extraction PDF

3.  SPIEGEL PDF