I love the cynicism of politicians using "decimalization" to rationalize inflation. Perhaps we can do it again to remove the penny, the nickel and the dime, and replace them with the "bit" (the "Shannon" ?) (1/2 of a quarter). At 03:42 PM 4/23/2014, Mike Stay wrote:

http://tywkiwdbi.blogspot.com/2012/11/thirty-nine-ninetieths-of-dollar.html

On Wed, Apr 23, 2014 at 4:23 PM, Dan Asimov <dasimov@earthlink.net> wrote:

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Total off-the-wall guess: In old financial conventions, some of which persist to this day, a year is reckoned as 360 days (which I guess simplified the arithmetic), and so one quarter of a year is 90 days.

--Dan

On Apr 23, 2014, at 3:13 PM, Bill Gosper <billgosper@gmail.com> wrote:

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R. Weyhrauch notes that http://digital.library.pitt.edu/cgi-bin/t/text/pageviewer-idx?c=darltext;cc=... (a document older than the dollarsign) prescribes a bunch of tariffs in 90ths instead of %. I thought I had a mathematical motivation, but was wrong. NeilB thought of a historical, rather than mathematical explanation, but it seems decreasingly plausible.

Can someone at least provide a good guess? -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com