- Pentadecimal
The pentadecimal (base-15) positional notation system is based on the number fifteen. Comparatively, the
decimal system is based on the number ten, thehexadecimal system is based on the number sixteen, and so on. Another name used for the base-15 system is quindecimal (although this term can be confused with quinary which is a base-5 notation system).Pentadecimal requires fifteen symbols. Since there are only ten common decimal digits, the notation can be extended by using letters A, B, C, D and E to represent values 10, 11, 12, 13 and 14, respectively. For example, decimal values 0 to 20 in pentadecimal would be: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, 10, 11, 12, 13, 14, 15. The pentadecimal number 373 would be 783 in decimal.
This numeric base is infrequently used. It finds applications in mathematics as well as fields such as telephony routing over IP (http://www.zvon.org/tmRFC/RFC3219/Output/chapter5.html) and other specialized uses.
Natural languages
The
Huli language ofPapua New Guinea is reported to have base-15 numerals [ Citation
last=Cheetham
first=Brian
title=Counting and Number in Huli
journal=Papua New Guinea Journal of Education
year=1978
volume=14
pages=16-35
url=http://www.uog.ac.pg/PUB08-Oct-03/cheetham.htm] . "Ngui" means 15, "ngui ki" means 15×2 = 30, and "ngui ngui" means 15×15 = 225.References
Wikimedia Foundation. 2010.
