<P> In Italy, where roads outside built - up areas have kilometre signs, major roads and motorways also mark 100 - metre subdivisionals, using Roman numerals from I to IX for the smaller intervals . The sign "IX 17" thus marks kilometre 17.9 . </P> <P> A notable exception to the use of Roman numerals in Europe is in Greece, where Greek numerals (based on the Greek alphabet) are generally used in contexts where Roman numerals would be used elsewhere . </P> <P> The number zero does not have its own Roman numeral, but the word nulla (the Latin word meaning "none") was used by medieval scholars in lieu of 0 . Dionysius Exiguus was known to use nulla alongside Roman numerals in 525 . About 725, Bede or one of his colleagues used the letter N, the initial of nulla or of nihil (the Latin word for "nothing"), in a table of epacts, all written in Roman numerals . </P> <P> Though the Romans used a decimal system for whole numbers, reflecting how they counted in Latin, they used a duodecimal system for fractions, because the divisibility of twelve (12 = 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). On coins, many of which had values that were duodecimal fractions of the unit as, they used a tally - like notational system based on twelfths and halves . A dot () indicated an uncia "twelfth", the source of the English words inch and ounce; dots were repeated for fractions up to five twelfths . Six twelfths (one half) was abbreviated as the letter S for semis "half". Uncia dots were added to S for fractions from seven to eleven twelfths, just as tallies were added to V for whole numbers from six to nine . </P>

What is the number zero in roman numerals