

The Romans also occasionally used a vinculum (called a titulus in the Middle Ages) over a Roman numeral to indicate multiplication by The Romans sometimes used multiple parentheses to denote nested multiplications by However, in the Middle Ages, the use of M became quite common.

It shouldĪlso be noted that the Romans themselves never wrote M for 1000, but instead wroteĮtc., and also occasionally wrote IM, IIM, etc. Recent practice, the strokes were sometimes written only on the sides, e.g., (Cajori 19993, p. 32). For large numbers, the Romans placed a partial frame around numbers (open at the bottom), which indicated that the framed number was toĪs illustrated above (Menninger 1992, p. 44 Cajori 1993, p. 32).
