Editing Signed-digit representation (section)

===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.