Mark E. Shoulson on Tue, 10 Jul 2012 21:22:36 -0400: > I'd not heard of using it as a subtraction symbol before, but it feels > to me like someone thought that the normal minus sign was too confusable > with an ordinary hyphen or something, maybe in a mixed presentation with > ordinary text and mathematical signs and negative numbers mixed > together, and was looking for something hyphen-looking but distinctive, > and used the ÷ since it looks hyphen-y and nobody seriously uses it for > division.
>From my speculatorium: The wikipedia articles about the obelis (÷) says that it was first used to signify "questionable source" for text critical edition of the Bible, back in the middle ages. (Sorry, if this sounded like the Hollywood version.) From negative/questionable to minus is a short way, no? It is also said that the + developed from a deformed & (et ligature). So may be the ÷ is a deformation of the +, again? When it come to the Russian/Polish/Italian usage to use ÷ to denote range, then - verbally, when I/we don't use "subtract" or "minus" as a verb, then we say [in Norwegian] "take (away) from". In other words: There is some kind of link between "minus" and "range", I feel. Thus, the usage as a range symobol, in my view is congruent with with the use as minus. As it has developed, however, the ÷ is used, both in the "range" usage and in the "minus" usage, as a more distinct signal. It separates the sign from characters it could be confused with. -- Leif H Silli
