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Latin numerical symbol (s) (noun), Latin numerical symbols (pl)
The origin of Latin counting symbols: There are some people who believe that the Latin numerical symbol V (5) represents the hand with all five fingers spread apart.

It is pleasant to think that I represents the upheld finger of Latin Numerical symbols and that V might symbolize the hand itself with all five fingers; so, one branch of the V would be the extended thumb; the other, the remaining fingers for "six", "seven", "eight", and "nine"; we would then have VI, VII, VIII, and VIIII.

—Compiled from Asimov on Numbers;
by Isaac Asimov; Mercury Press, Inc.;
New York; 1966; page 9.
This entry is located in the following units: numer-, number- (page 3) syn-, sy-, sym-, syl-, sys- (page 6)