Casting Out Nines

Author

Eric W. Weisstein
April 14, 2004

This notebook downloaded from http://mathworld.wolfram.com/notebooks/Arithmetic/CastingOutNines.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/CastingOutNines.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

Example

12345 67890

(Plus@@IntegerDigits[#]&/@{12345,67890})

Times@@%

Plus@@IntegerDigits[838102050]

Mod[#,9]&/@{450,27}