Hans Aberg, Tue, 10 Jul 2012 22:41:26 +0200: > On 10 Jul 2012, at 21:30, Asmus Freytag wrote: >> On 7/10/2012 3:50 AM, Leif Halvard Silli wrote: >>> Asmus Freytag, Mon, 09 Jul 2012 19:32:47 -0700: >>>> The European use (this is not limited to Scandinavia) >>> Thanks. It seems to me that that this tradition is not without a link >>> to the (also) European tradition of *not* using the DIVISION SIGN (÷) >>> for division. >> >> Is it _ever_ used for division? I'm curious, right now I can't >> recall ever having seen an example. > > The WP "Obelus" article says that it was used as a sign for division > in 1659, otherwise used for subtraction, continued in Norway, and > until recently, in Denmark. > > https://en.wikipedia.org/wiki/Obelus
Thanks. Scandinavia's history indicates that if known in Denmark, Norway and Finland, then it should be known on Iceland and in Sweden too. Though, Finland could have influx from Russia too, se below. That the English Wikipedia article mentions the current use as hyphen/dash in Italia and Poland is also interesting (see below). Here is what the different Wikipedias says: * Russian: both ÷ and : can be used to express range: "For example, «5÷10» can refer to the range [5, 10], that is from 5 to 10 inclusive." [1a] Russian Wikipedia is verified by a book found at Art Lebedev's web site.[1b] The chapter 6 says, in my rough translation: "In technical literature, one does, according to tradition, use the sign ÷ between numbers in digit form." (The book lists several other ways to list intervals too.) * Italian: lists "range" as _the_ use, and only adds, that "It is sometimes used as a symbol of the division, in particular on electronic calculators".[2] * French: starts by saying that ÷ and : are mathematical synonyms. But when it states that Belgium recommends : in schools, then the French audience apparently don't trust it 'just like that' as there is a request for verification.[3] * Spanish: the ÷ as subtraction symbol is known from Scandinavia and Germany.[4] * German: The most interesting detail (apart from the fact that it does not mention ÷ as minus sign) is how it seeks to correct the "misconception" that the ÷ can be called "the English division sign" - after all (and despite the Spanish article's claim about Switzerland): "Sein Ursprung liegt allerdings in Deutschland."[5] But at least I am very satisfied to see in the German article that "most of the world" uses the colon, and not the ÷ as the division sign. * Bulgarian: Its tone is as if describing a foreign object.[6a] That the article on division hence doesn't mention the ÷ at all (it only mentions solidus and colon) is not surprising.[6b] All/Most of the Wikipedia articles has some note indicating that ÷ is from English usage ... Btw, the venerable Danish Salomonsens conversional encyclopedia, the 1924 edition, says, that subtraction, quote: "is written a – b or a ÷ b, where the – and the ÷ is called the minus sign". [7] So it sounds as if it saw it as shapes of the very same character. And this also makes sense when we consider that we historically apparently never used the ÷ for division. PS: It was especially interesting to follow Wikipedia's link to Jeff Miller's article.[8] He mentioned the use of the FULL STOP as multiplication symbol. Which allows me to say, that the Norwegian book from 1920 that I pointed in an earlier message did both use the multiplication sign (×), but here and there, it uses the FULL STOP as multiplication symbol… For instance 16 * 11 looks like the single number 16.11 … (Sometimes it shifts between . and × from line to line - may be due to conventions I do not know.) Fortunately, when expressing division (with the colon), the spacing is more sane - 176 : 30 … So may be the typographer worked a little fast, or was confused by the manuscript ... Miller also mentions the vinculum, for division. This seems known in many "cultures", including my own, but I would be lost if I were to type it somehow. (May be MathML can help ...) [1a] https://ru.wikipedia.org/wiki/Знак_деления [1b] http://www.artlebedev.ru/everything/izdal/spravochnik-izdatelya-i-avtora/ [2] https://it.wikipedia.org/wiki/Obelo [3] https://fr.wikipedia.org/wiki/Obélus [4] https://es.wikipedia.org/wiki/Óbelo [5] https://de.wikipedia.org/wiki/Geteiltzeichen [6a] https://bg.wikipedia.org/wiki/Обелос [6b] https://bg.wikipedia.org/wiki/Деление |7] http://runeberg.org/salmonsen/2/22/0558.html [8] http://jeff560.tripod.com/operation.html -- Leif Halvard Silli
