Commas and Decimal Points in Currency Notations

Date: 11/08/2007 at 11:53:34
From: Katherine
Subject: Decimal point versus comma use in currency

Why do the Eurolanders use the comma in currency instead of the 
decimal point as in the States?

Date: 11/09/2007 at 22:20:29
From: Doctor Peterson
Subject: Re: Decimal point versus comma use in currency

Hi, Katherine.

During the 1600's there were many competing notations for decimals, of
which the comma and period were the two winners.  Here's what Cajori,
in A History of Mathematical Notations, says about one point in the
conflict (p. 328):

  In the eighteenth century, trials of strength between the comma
  and the dot as the separatrix were complicated by the fact that
  Leibniz had proposed the dot as the symbol of multiplication ....
  As a symbol for multiplication the dot was seldom used in England
  during the eighteenth century, Oughtred's X being generally
  preferred.  For this reason, the dot as a separatrix enjoyed an
  advantage in England during the eighteenth century which it did
  not enjoy on the continent.

In the end, the comma won on the continent of Europe; the dot was used
in England, though commonly raised rather than on the line (with the
low dot used for multiplication).  In America the usage varied at
first, but has settled down to the low dot for the decimal separator,
and a raised dot for multiplication. 

If you have any further questions, feel free to write back.

- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/