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A comment on How to Divide any number By 9, 90, 900 and so on in just 5 seconds .

Re:How to Divide any number By 9, 90, 900 and so on in just ... by no-espam on Tuesday March 06, 2012 @08:48AM (#3670935)
Professor Trachtenberg (early 1900) comes to mind for doing speed math.
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Re:How to Divide any number By 9, 90, 900 and so on in just ... by no-espam on Tuesday March 06, 2012 @09:59AM (#3671255)
Wow, downvoted for posting info related to a professor who was held in nazi concentration camp and kept his mind lucid with math?

http://en.wikipedia.org/wiki/Trachtenberg_system

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Re:How to Divide any number By 9, 90, 900 and so on in just ... by downx3 on Tuesday March 06, 2012 @10:21AM (#3671374)
+1 for the Trachtenberg system. I only wish we were taught these methods at school, in addition to the 'normal' way...
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