The Collaborative International Dictionary of English v.0.48:

decimalization \decimalization\ n.
   the act of changing to a decimal system; as, the
   decimalization of the British currency.

   Syn: decimalisation.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Decimalize \Dec"i*mal*ize\, v. t.
   to convert the dominant units of measure (e.g. of currency)
   to a decimal-based system; to reduce to a decimal system; as,
   to decimalize the currency. -- Dec`i*mal*i*za"tion, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

decimalization
    n 1: the act of changing to a decimal system; "the
         decimalization of British currency" [syn: decimalization,
         decimalisation]