Numeral systems are classified here as to whether they use
positional notation (also known as place-value notation), and further categorized by
radix or base.
Standard positional numeral systems might use
LEDs to express binary values. In this clock, each column of LEDs shows a
binary-coded decimal numeral of the traditional
sexagesimal time.|class=skin-invert-image The common names are derived
somewhat arbitrarily from a mix of
Latin and
Greek, in some cases including roots from both languages within a single name. There have been some proposals for standardisation. ===
Non-standard positional numeral systems=== ====
Bijective numeration==== ====
Signed-digit representation==== ====
Complex bases==== ====
Non-integer bases==== ====
n-adic number==== ====
Mixed radix==== •
Factorial number system {1, 2, 3, 4, 5, 6, ...} • Even double factorial number system {2, 4, 6, 8, 10, 12, ...} • Odd double factorial number system {1, 3, 5, 7, 9, 11, ...} •
Primorial number system {2, 3, 5, 7, 11, 13, ...} •
Fibonorial number system {1, 2, 3, 5, 8, 13, ...} • {60, 60, 24, 7} in timekeeping • {60, 60, 24, 30 (or 31 or 28 or 29), 12, 10, 10, 10} in timekeeping • (12, 20) traditional English monetary system (£sd) • (20, 18, 13) Maya timekeeping
Other •
Quote notation •
Redundant binary representation •
Hereditary base-n notation •
Asymmetric numeral systems optimized for non-uniform probability distribution of symbols •
Combinatorial number system Non-positional notation All known numeral systems developed before the
Babylonian numerals are non-positional, as are many developed later, such as the
Roman numerals. The French Cistercian monks created
their own numeral system. ==See also==