Obelus - Revision history

Beza 1598: /* External links */

2016-03-10T09:50:59Z

External links

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	[[Category:Typography]]		[[Category:Typography]]
	[[Category:Division]]		[[Category:Division]]

			{{Donate}}

Nick: Protected "Obelus" [edit=autoconfirmed:move=autoconfirmed]

2010-09-18T04:09:07Z

Protected "Obelus" [edit=autoconfirmed:move=autoconfirmed]

← Older revision	Revision as of 04:09, 18 September 2010
(No difference)

Nick: /* External links */

2010-09-18T04:09:01Z

External links

← Older revision		Revision as of 04:09, 18 September 2010
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	* [http://jeff560.tripod.com/operation.html Jeff Miller: ''Earliest Uses of Various Mathematical Symbols'']		* [http://jeff560.tripod.com/operation.html Jeff Miller: ''Earliest Uses of Various Mathematical Symbols'']
	* [http://www.worldwidewords.org/articles/signs.htm Michael Quinion: ''Where our arithmetic symbols come from'']		* [http://www.worldwidewords.org/articles/signs.htm Michael Quinion: ''Where our arithmetic symbols come from'']
			* [http://en.wikipedia.org/w/index.php?title=Obelus&action=edit Wikipedia Article on Obelus]

	[[Category:Mathematical symbols]]		[[Category:Mathematical symbols]]
	[[Category:Typography]]		[[Category:Typography]]
	[[Category:Division]]		[[Category:Division]]

Nick: /* Notes */

2010-09-18T04:08:30Z

Notes

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	==Notes==		==Notes==

	* 1 [[Burnett Hillman Streeter]], ''[[The Four Gospels]]'', London, Macmillan, 1924 [http://www.katapi.org.uk/4Gospels/Ch5.htm]   The Aristarchus referred to was presumably [[Aristarchus of Samothrace]].		* 1. [[Burnett Hillman Streeter]], ''[[The Four Gospels]]'', London, Macmillan, 1924 [http://www.katapi.org.uk/4Gospels/Ch5.htm]   The Aristarchus referred to was presumably [[Aristarchus of Samothrace]].

	== External links ==		== External links ==

Nick: /* Notes */

2010-09-18T04:08:25Z

Notes

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	==Notes==		==Notes==
	* 1 [[Burnett Hillman Streeter]], ''[[The Four Gospels]]'', London, Macmillan, 1924 [http://www.katapi.org.uk/4Gospels/Ch5.htm]   The Aristarchus referred to was presumably [[Aristarchus of Samothrace]].
			* 1 [[Burnett Hillman Streeter]], ''[[The Four Gospels]]'', London, Macmillan, 1924 [http://www.katapi.org.uk/4Gospels/Ch5.htm]   The Aristarchus referred to was presumably [[Aristarchus of Samothrace]].

	== External links ==		== External links ==

Nick: /* Notes */

2010-09-18T04:08:18Z

Notes

← Older revision		Revision as of 04:08, 18 September 2010
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	==Notes==		==Notes==
			* 1 [[Burnett Hillman Streeter]], ''[[The Four Gospels]]'', London, Macmillan, 1924 [http://www.katapi.org.uk/4Gospels/Ch5.htm]   The Aristarchus referred to was presumably [[Aristarchus of Samothrace]].

	== External links ==		== External links ==

Nick: New page: The division sign. An '''obelus''' ('''÷''') (plural, '''obeli''') is a symbol consisting of a short line with dots above and below. It is main...

2010-09-18T04:07:02Z

New page: thumb|right|The division sign. An '''obelus''' ('''÷''') (plural, '''obeli''') is a symbol consisting of a short line with dots above and below. It is main...

New page

[[Image:Division Sign(a).png|thumb|right|The division sign.]]

An '''obelus''' ('''÷''') (plural, '''obeli''') is a symbol consisting of a short line with dots above and below. It is mainly used to represent the mathematical operation of [[Division (mathematics)|division]]. It is therefore also known as a '''division sign'''.

== History ==
The word "obelus" comes from the [[Greek language|Greek]] word for a sharpened stick, spit, or pointed pillar. This is the same root as that of the word "[[obelisk]]". Originally this sign (or a plain line) was [[obelism|used in ancient manuscripts to mark passages]] that were suspected of being corrupted or spurious.

::The obelus, invented by Aristarchus to mark suspected passages in Homer, is frequent in MSS. [i.e. [[manuscript]]s] of the Gospel to mark just those sections, like the Pericope in John, which modern editors reject. The first corrector of א, probably the contemporary διορθωτής, was at pains to enclose in brackets and mark with dots for deletion two famous passages in Luke written by the original scribe which, being absent from B W 579 and the Egyptian versions, we infer were not accepted in the text at that time dominant in Alexandria, viz. the incident of the "Bloody Sweat" in Gethsemane (Lk.xxi.43 f.) and the saying "Father forgive them" (Lk.xi.34).<sup>[]</sup>

The obelus was first used as a symbol for division in 1659 in the [[algebra]] book ''Teutsche Algebra'' by [[Johann Rahn]]. Some think that [[John Pell]], who edited the book, may have been responsible for this use of the symbol. The obelus had been used by some writers to represent subtraction, and that usage continued in some parts of Europe (including [[Norway]] and, until fairly recently, [[Denmark]]). [[Unicode]] has a related character, ⁒, called "commercial minus sign", located at U+2052 (HTML <tt>&x2052;</tt>).

== Uses==
The obelus was used occasionally in [[Polish language]] typography to represent ranges (such as the range ''1÷10''), although this usage has been mostly discontinued. As of 2007, it was also used to indicate a range in [[Italian language|Italian]] documents (for example, ''40% ÷ 50%'' would indicate 40 percent to 50 percent).

The obelus is used primarily as a symbol for division (as on a [[calculator]]) and as an operator in elementary [[arithmetic]]. Division is also signified in other ways — usually as a [[fraction]]: by writing the operands one above the other and separated by a line, or on the same line separated by a [[Solidus (punctuation)|solidus]] or [[Slash (punctuation)|slash]].

In many non-Anglophone countries, the [[colon (punctuation)|colon]] is used as a division sign: “''a'' divided by ''b''” is written as ''a'' : ''b'', and this is widely used to indicate a [[ratio]].

On a Windows computer, the obelus is produced with [[Alt key|Alt]]+0247 or [[Alt key|Alt]]+246 on the number pad. On a Macintosh, it is produced with [[Option key|Option]] + / (Option + slash). On UNIX-based systems using [[GNU Screen|Screen]] or X with a [[Compose key]] enabled, it can be produced by composing : (colon) and - (minus), though this is locale- and setting-dependent. It may also be input by Unicode code-point on GTK-based applications by pressing Control + Shift + U, followed by the codepoint in hexadecimal (<tt>F7</tt>) and terminated by <tt>return</tt>.

In the [[Unicode]] character set, the obelus is known as the “division sign” and has the code point U+00F7. In [[HTML]], it can be [[Character encodings in HTML|encoded]] as <tt>&divide;</tt> or <tt>&#xF7;</tt> (at [[List of XML and HTML character entity references|HTML level]] 3.2), or as <tt>&#247;</tt>.

==Notes==

== External links ==
* [http://jeff560.tripod.com/operation.html Jeff Miller: ''Earliest Uses of Various Mathematical Symbols'']
* [http://www.worldwidewords.org/articles/signs.htm Michael Quinion: ''Where our arithmetic symbols come from'']

[[Category:Mathematical symbols]]
[[Category:Typography]]
[[Category:Division]]