WordNet (r) 3.0 (2006):

floating-point representation system
    n 1: a radix numeration system in which the location of the
         decimal point is indicated by an exponent of the radix; in
         the floating-point representation system, 0.0012 is
         represented as 0.12-2 where -2 is the exponent [syn:
         floating-point notation, floating-point representation
         system]