Roman Numerals: Difference between revisions
Changed factors of 12 from 22 and 3 to 2, 2, and 3.
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The base "Roman fraction" is S, indicating 1⁄2. The use of S (as in VIIS to indicate 7 1⁄2) is attested in some ancient inscriptions, but while Roman numerals for whole numbers are decimal S does not correspond to 5⁄10, as one might expect, but 6⁄12. This is because Roman Numeral system for numbers less than 0 are duodecimal in base (base-12). | The base "Roman fraction" is S, indicating 1⁄2. The use of S (as in VIIS to indicate 7 1⁄2) is attested in some ancient inscriptions, but while Roman numerals for whole numbers are decimal S does not correspond to 5⁄10, as one might expect, but 6⁄12. This is because Roman Numeral system for numbers less than 0 are duodecimal in base (base-12). | ||
The Romans used a duodecimal rather than a decimal system for fractions, as the divisibility of twelve (12 = | The Romans used a duodecimal rather than a decimal system for fractions, as the divisibility of twelve (12 = 2 × 2 × 3) makes it easier to handle the common fractions of 1⁄3 and 1⁄4 than does a system based on ten (10 = 2 × 5). | ||
Notation for fractions other than 1⁄2 is mainly found on surviving Roman coins, many of which had values that were duodecimal fractions of the unit as. Fractions less than 1⁄2 are indicated by a dot ({{rn|·}}) for each uncia "twelfth", the source of the English words inch and ounce; dots are repeated for fractions up to five twelfths. Six twelfths (one half), is S for semis "half". Uncia dots were added to {{rn|S}} for fractions from seven to eleven twelfths, just as tallies were added to {{rn|V}} for whole numbers from six to nine. | Notation for fractions other than 1⁄2 is mainly found on surviving Roman coins, many of which had values that were duodecimal fractions of the unit as. Fractions less than 1⁄2 are indicated by a dot ({{rn|·}}) for each uncia "twelfth", the source of the English words inch and ounce; dots are repeated for fractions up to five twelfths. Six twelfths (one half), is S for semis "half". Uncia dots were added to {{rn|S}} for fractions from seven to eleven twelfths, just as tallies were added to {{rn|V}} for whole numbers from six to nine. | ||