History Main / AlternativeNumberSystem

-->-- Music/TomLehrer, ''New Math''.

* Roman numerals could be considered a combination of base 5 and base 10. With unique symbols for 1 (I), 5 (V), 10 (X), 50 (L), 100 (C), 500 (D), and 1,000 (M). All other numbers being an additive or subtractive combination of the unique signs.

** Some languages are weirder: Arabic stays little-endian until ''100''. So "16" is ''sitta-`ashar'' (six-ten) and "36" is ''sitta-wa-thalaathuun'' (six-and-thirty), but "136" is ''mi'ah wa sitta wa thalaathuun'' (a-hundred-and-six-and-thirty). This, however, is a relatively modern construction. Like the language itself, the numbers were read from right to left; "sitta wa thalaathuun wa mi'ah" (six-and-thirty-and-hundred)

* Up until the 1970s, British currency was a mix of base 12 (12 pence to the shilling), and base 20 (20 shillings to the pound). They were the last first world nation to switch to a decimal based currency.

* The origin of base 10 is, of course, that we (usually) have a total of 10 fingers in our hands, like other terrestrial vertebrates in their forward claws or whatever[[note]]Those that have less have lost them during their evolution[[/note]], as a legacy of the ancestor of all vertebrates. Had that creature had [[https://en.wikipedia.org/wiki/Polydactyly_in_early_tetrapods a different number of them]], it's very likely we'd be counting in base (# of fingers in our two hands).

* In Leo Frankowski's ''The Cross Time Engineer'' series, the new civilization Conrad Stargard starts up in Medieval Europe uses base 12 mathematics, because Stargard believes it's more useful than decimal.

* The ''gukuy'' in EricFlint's ''Literature/MotherOfDemons'' count using an eight-base system.

* The ''SchoolhouseRock'' music video for [[https://www.youtube.com/watch?v=_uJsoZheTR4 "Little Twelvetoes"]] briefly touches on the idea of what counting with a base-twelve system would be like, and demonstrates with the titular twelve-fingered alien character.
* In TheSimpsons Principal Skinner wishes he had enough funding for his school to buy, amongst other things, "math books that don't have that base 6 crap in them". This is almost certainly a reference to New Math, a way of teaching mathematics that was briefly popular in TheSixties but very rapidly fell out of favour.

* Done subtly in ''WesternAnimation/Animaniacs''. Snow White imprisons Dot for being too cute, and Dot counts the time in hashmarks that only have four strokes each... presumably because [[FourFingeredHands she's a cartoon character]].

* In TheFrantics' sketch [[http://www.youtube.com/watch?v=fjFaKD9BuOc "Roman Numerals"]] a Roman citizen is baffled by the new decimal system.

* It's never mentioned in the books themselves, or the series, but the "Gallifreyan numerals" used on the spines and chapter headings of the ''Series/DoctorWho'' New Series Adventures (9th and 10th Doctors) are in base 7.

-->-- TomLehrer, ''New Math''.

** In older English, it's also not uncommon to see constructions like "six and thirty", which is still how German, parts of Danish and old-fashioned Norwegian do it.

* During ''VideoGame/{{Portal}}'''s boss fight, after GLaDOS takes a missile hit she'll announce "Two plus two equals... ''ten!'' In base four I'm fine!"

* Currency in the ''Literature/HarryPotter'' universe is a mixture of base 17 (17 sickles to the galleon) and base 29 (29 knuts to the sickle). This is possibly a joke based on the currency units of RL Britain until the 70s (Though at least they didn't use prime numbers).

* The rabbits of ''Literature/WatershipDown'' can count up to four, presumably because that's how many paws they have. The number "hrair" In their language of Lapine means "any quantity greater than four" and/or "too many to count"; depending on context, it may also be translated into English as "five" or "a thousand."

** The D'ni have a base 25 system, in keeping with the games' general tendency to use powers of five as {{Arc Number}}s.
** In ''VideoGame/MystIIIExile'', Saavedro's journal pages are numbered in base 5.

* A significant portion of the game ''{{VideoGame/Rama}}'', based on Arthur C. Clarke's [[RendezvousWithRama novel]] series of the [[TheGameOfTheBook same name]], involves solving mathematical puzzles based on the native number systems of the Avians (base 16) and Octospiders (base 8). (Which is at odds with the Ramans, who use base 3. Neither the Avians nor the Octospiders are Ramans. They're just samples of other space-faring species that the Ramans had gathered.)

* The aliens in the ''[[RendezvousWithRama Rama]]'' books appear to use base 3.

* At one point in ''Fangs of K'aath'', the FunnyAnimal civilization's use of base 8 is explained (due, again, to their fingers) by one character to another; they write 8 as "10". They are apparently fond of mathematics, too, which is fitting, as this particular FantasyCounterpartCulture is based on the medieval Islamic lands.
* In the ''Literature/Eldraeverse'', the Eldrae use base 12, and had a brief flirtation with base 16.

* In ''{{Traveller}}'', the various alien species use different base mathematics. The Aslan use Base 8, the Hivers use Base 16, and the Droyne use Base 6. Most of the various {{Human Alien}}s, as well as the Vargr, use Base 10.

* In ''WebComic/{{Housepets}}'', a mouse named Spo came from a very large family. How large? The sibling born immediately after him [[http://www.housepetscomic.com/2009/02/23/their-naming-conventions-had-a-cover-charge/ was named Spp]]...
* In ''WebComic/GirlGenius''' world of [[MadScientist mad science]] there's bound to be examples showing up: "Tell the landlord that he is to stop trying to make change in base eight, or he'll pay his taxes in base twelve."

->"Base eight is just like base ten, really. [[FourFingeredHands If you're missing two fingers]]."