Year 5 (V) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Messalla and Cinna (or, less frequently, year 758 Ab urbe condita). The denomination 5 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

5 (five ) is a number, numeral, and glyph. It is the natural number following 4 and preceding 6.

5* (pronounced "five star") is a television channel in the United Kingdom owned by Viacom International Media Networks Europe. It is a sister channel of Channel 5 and 5USA. The channel was launched as "Five Life" on 15 October 2006, and was rebranded as "Fiver" on 28 April 2008, and "5*" on 7 March 2011. The channel is available on digital television via Freesat, Freeview, Sky, and Virgin Media. 5* broadcasts between 09:00 and 00:00. It was originally launched by RTL Group (the former owner) as part of their multi-channel strategy, which all other analogue broadcasters, such as ITV plc and Channel 4, had already achieved.

An emoticon ( or ), etymologically a portmanteau of emotion and icon, is a metacommunicative pictorial representation of a facial expression that, in the absence of body language and prosody, serves to draw a receiver's attention to the tenor or temper of a sender's nominal non-verbal communication, changing and improving its interpretation. It expresses — usually by means of punctuation marks (though it can include numbers and letters) — a person's feelings or mood, though as emoticons have become more popular, some devices have provided stylized pictures that do not use punctuation.

In arithmetic and algebra, the fifth power of a number n is the result of multiplying five instances of n together. So:

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One half is the irreducible fraction resulting from dividing one by two , or the fraction resulting from dividing any number by its double. Multiplication by one half is equivalent to division by two, or halving; conversely, division by one half is equivalent to multiplication by two, or "doubling". One half appears often in mathematical equations, recipes, measurements, etc. Half can also be said to be one part of something divided into two equal parts.

Unicode has subscripted and superscripted versions of a number of characters including a full set of arabic numerals. These characters allow any polynomial,  chemical and certain other equations to be represented in plain text without using any form of markup like HTML or TeX.