Source : Free On-Line Dictionary of Computing

ARITH-MATIC
     
         An extension of {Grace Hopper}'s {A-2} programming
        language, developed in about 1955.  ARITH-MATIC was originally
        known as A-3, but was renamed by the marketing department of
        {Remington Rand UNIVAC}.
     
        {(http://cispom.boisestate.edu/cis221emaxson/hophtm.htm)}.
     
        [How was A-2 extended?]
     
        (2001-01-27)