#digit__figure  one of the elements that collectively form a system of numbers; "0 and 1 are digits"
  supertype:  #integer__whole_number__wholenumber  any of the natural numbers (positive or negative) or zero
  subtype:  #binary_digit  either 0 or 1 in binary notation
  subtype:  #octal_digit__octaldigit  a digit from 0 to 7 in octal notation
  subtype:  #decimal_digit__decimaldigit  a digit from 0 to 9 in decimal notation
  subtype:  #significant_digit__significantdigit__significant_figure__significantfigure  any digit of a number that is known with certainty; any digit of a number beginning with the leftmost non-zero digit and ending with the rightmost non-zero digit (or a zero considered to be the exact value); "he calculated the answer to four significant figures"
  subtype:  #zero__0__nought__cipher__cypher  a mathematical element that when added to another number yields the same number
  subtype:  #1__one__i__ace__unity  the smallest whole number or a numeral representing this number; "he has the one but will need a two and three to go with it"; "they had lunch at one"
     subtype:  #monas__mona__monad  a singular metaphysical entity from which material properties are said to derive
     subtype:  #singleton.1__singleton  a single object (as distinguished from a pair)
  subtype:  #two__2__II__deuce  the cardinal number that is the sum of one and one or a numeral representing this number
     subtype:  #craps__crap__snake_eyes  when two dice are thrown and both come up showing one spot the results is called `craps' or `snake eyes'
     subtype:  #doubleton__couple__pair__twosome__twain__brace__span__yoke__couplet__distich__duo__duet__dyad__duad  two items of the same kind
  subtype:  #three__3__III__trio__threesome__tierce__leash__troika__triad__trine__trinity__ternary__ternion__triplet__tercet__terzetto__trey__deuce-ace__deuceace  the cardinal number that is the sum of one and one and one
  subtype:  #four__4__IV__tetrad__quatern__quaternion__quaternary__quaternity__quartet__quadruplet__foursome__Little_Joe  the cardinal number that is the sum of three and one
  subtype:  #five__5__V__cinque__quint__quintet__fivesome__quintuplet__pentad__fin__phoebe__Little_Phoebe  the cardinal number that is the sum of four and one
  subtype:  #six__VI__sixer__sise__Captain_Hicks__half_a_dozen__sextet__sestet__sextuplet__hexad  the cardinal number that is the sum of five and one
  subtype:  #seven__7__VII__sevener__septet  the cardinal number that is the sum of six and one
  subtype:  #eight__8__viii__eighter__eighterfromdecatur__octad__ogdoad__octonary__octet  the cardinal number that is the sum of seven and one
  subtype:  #nine__9__IX__niner__Nina_from_Carolina__ennead  the cardinal number that is the sum of eight and one

No statement uses or specializes #digit; click here to add one.