Elementary division rules enable you to quickly determine small factors of a given number. These rules are useful for reduction of fractions and for rapid determination of simple factors.
Digital Divisibility Tests
From Carlos Rivera's Prime Puzzles and Problems collection. Carlos asks for the general divisibility rules for any prime number.
From the Furman University Electronic Journal of Undergraduate Mathematics. Apoorva Khare's paper is available as an abstract, DVI, and PostScript.
Explaining the Divisibility Rules
Proof of the elementary division rules, plus some lesser-known rules for larger divisors and other bases.
Last update:March 15, 2015 at 19:19:27 UTC