Editing Signed-digit representation (section)

==In written and spoken language==
===Indo-Aryan languages===
The oral and written forms of numbers in the [[Indo-Aryan languages]] use a negative numeral (e.g., "un" in [[Hindi]] and [[Bengali language|Bengali]], "un" or "unna" in [[Punjabi_Language|Punjabi]], "ekon" in [[Marathi_Language|Marathi]]) for the numbers between 11 and 90 that end with a nine. The numbers followed by their names are shown for Punjabi below (the prefix "ik" means "one"):<ref>[http://quizlet.com/16314536/punjabi-numbers-1-100-flash-cards/ Punjabi numbers] from [[Quizlet]]</ref> 
* 19 unni, 20 vih, 21 ikki
* 29 unatti, 30 tih, 31 ikatti
* 39 untali, 40 chali, 41 iktali
* 49 unanja, 50 panjah, 51 ikvanja
* 59 unahat, 60 sath, 61 ikahat
* 69 unattar, 70 sattar, 71 ikhattar
* 79 unasi, 80 assi, 81 ikiasi
* 89 unanve, 90 nabbe, 91 ikinnaven.

Similarly, the [[Sesotho]] language utilizes negative numerals to form 8's and 9's.
* 8 robeli (/Ro-bay-dee/)  meaning "break two" i.e. two fingers down
* 9 robong (/Ro-bong/) meaning "break one" i.e. one finger down

===Classical Latin===
In [[Classical Latin]],<ref>J. Matthew Harrington (2016) [https://cpb-us-w2.wpmucdn.com/campuspress.yale.edu/dist/4/3253/files/2018/08/Harrington-Latin-Grammar-2016.pdf Synopsis of Ancient Latin Grammar]</ref> integers 18 and 19 did not even have a spoken, nor written form including corresponding parts for "eight" or "nine" in practice - despite them being in existence. Instead, in Classic Latin,

*18 = duodēvīgintī ("two taken from twenty"), (IIXX or XIIX),
*19 = ūndēvīgintī ("one taken from twenty"), (IXX or XIX)
*20 = vīgintī ("twenty"), (XX).

For upcoming integer numerals [28, 29, 38, 39, ..., 88, 89] the additive form in the language had been much more common, however, for the listed numbers, the above form was still preferred. Hence, approaching thirty, numerals were expressed as:<ref>{{Citation |title=duodetriginta |date=2020-03-25 |work=Wiktionary, the free dictionary |url=https://en.wiktionary.org/w/index.php?title=duodetriginta&oldid=58999568 |access-date=2024-04-07 |language=en}}</ref>

*28 = duodētrīgintā ("two taken from thirty"), less frequently also yet vīgintī octō / octō et vīgintī ("twenty eight / eight and twenty"), (IIXXX or XXIIX versus XXVIII, latter having been fully outcompeted.)
*29 = ūndētrīgintā ("one taken from thirty") despite the less preferred form was also at their disposal.

This is one of the main foundations of contemporary historians' reasoning, explaining why the subtractive I- and II- was so common in this range of cardinals compared to other ranges. Numerals 98 and 99 could also be expressed in both forms, yet "two to hundred" might have sounded a bit odd - clear evidence is the scarce occurrence of these numbers written down in a subtractive fashion in authentic sources.

===Finnish Language===
There is yet another language having this feature (by now, only in traces), however, still in active use today. This is the [[Finnish Language]], where the (spelled out) numerals are used this way should a digit of 8 or 9 occur. The scheme is like this:<ref>{{Cite web |title=Kielitoimiston sanakirja |url=https://www.kielitoimistonsanakirja.fi/#/perusluku |access-date=2024-04-07 |website=www.kielitoimistonsanakirja.fi}}</ref>

*1 = "yksi" (Note: yhd- or yht- mostly when about to be declined; e.g. "yhdessä" = "together, as one [entity]")
*2 = "kaksi" (Also note: kahde-, kahte- when declined)
*3 = "kolme"
*4 = "neljä"
...
*7 = "seitsemän"
*8 = "kah(d)eksan" (two left [for it to reach it])
*9 = "yh(d)eksän" (one left [for it to reach it])
*10 = "kymmenen" (ten)

Above list is no special case, it consequently appears in larger cardinals as well, e.g.:
*399 = "kolmesataayhdeksänkymmentäyhdeksän"

Emphasizing of these attributes stay present even in the shortest colloquial forms of numerals:

*1 = "yy"
*2 = "kaa"
*3 = "koo"
...
*7 = "seiska"
*8 = "kasi"
*9 = "ysi"
*10 = "kymppi"

However, this phenomenon has no influence on written numerals, the Finnish use the standard Western-Arabic decimal notation.

===Time keeping===
In the [[English language]] it is common to refer to times as, for example, 'seven to three', 'to' performing the negation.