Number = a*10 + b Rearranged = b*10 + a Difference = (b - a)*10 + (a - b) = 9*(b - a)
Frank C. Wimberly 140 Calle Ojo Feliz Santa Fe, NM 87505 wimber...@gmail.com wimbe...@cal.berkeley.edu Phone: (505) 995-8715 Cell: (505) 670-9918 -----Original Message----- From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Robert J. Cordingley Sent: Monday, October 08, 2012 10:21 AM To: The Friday Morning Applied Complexity Coffee Group Subject: [FRIAM] Nines: Trivia Question? I probably should know this... So when you rearrange the digits of a number (>9) and take the difference, it is divisible by nine. A result that sometimes points to accounting errors. If the numbers are not base 10 the result is divisible by (base-1). What is the associated theorem for this? Thanks Robert ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
