The pentadecimal (base-15) positional notation system is based on the number fifteen. Comparatively, the decimal system is based on the number ten, the hexadecimal 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.