Language, where the (spelled out) numerals are used this way should a digit of 8 or 9 occur. The scheme is like this: 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. Other systems There exist other signed-digit bases such that the base . A notable examples of this is Booth encoding, which has a digit set with and , but which uses a base . The standard binary numeral system would only use digits of value . Note that non-standard signed-digit representations are not unique. For instance: The non-adjacent form (NAF) of Booth encoding does guarantee a unique representation for every integer value. However, this only applies for integer values. For example, consider the following repeating binary numbers in NAF, See also Balanced ternary Negative base Redundant binary representation Notes and references J. P. Balantine (1925) "A Digit for Negative One", American Mathematical Monthly 32:302. Lui Han, Dongdong Chen, Seok-Bum Ko, Khan A. Wahid "Non-speculative Decimal Signed Digit Adder" from Department of Electrical and Computer Engineering, University of Saskatchewan. Non-standard positional numeral systems Number theory Ring theory Arithmetic dynamics Coding theory Formal languages