From: "Peter L. Peres" To: Sent: Sunday, June 10, 2001 3:38 PM Subject: Re: [pic]: 9 > The theorem that 'a number is divisible by 3 if the sum of its digits is > divisible by 3' is not valid in base 2 and afaik in no other base than 10. I believe it is valid in any base 3N+1, when N is a positive integer. It is in particular valid in base 4, which is the basis behind the rather elegant divide-by-three check tha was mentioned here in the past few days. Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu