The Roman number system was flawed. It had no zero (0) and no single method for counting above several thousand units. Lines were often placed over numerals to indicate multiples of their value.

In Rome the word nulla (the Latin word meaning "none") was used in lieu of zero. Also, it was used in other societies until the medieval ages. Dionysius Exiguus, a 6th-century monk, in 525 AD was known to use nulla alongside Roman numerals.

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