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From: parnass@ihuxf.UUCP
Newsgroups: net.math
Subject: interesting division by 3 property
Message-ID: <657@ihuxf.UUCP>
Date: Tue, 23-Aug-83 11:54:45 EDT
Article-I.D.: ihuxf.657
Posted: Tue Aug 23 11:54:45 1983
Date-Received: Wed, 24-Aug-83 12:52:44 EDT
Organization: BTL Naperville, Il.
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       One of my favorite arithmetic shortcuts is:

	  o+ any	integer	N is divisible by  3  if  the  sum  of	N's
	    digits is divisible	by 3.


       I  sometimes  use  this	property   recursively	 to   avoid
       performing long division.
-- 
 ============================================================================
   Robert S. Parnass, Bell Laboratories   ihnp4!ihuxf!parnass  (312)979-5760