http://www.mathsisfun.com/divisibility-rules.html

http://math.about.com/library/bldivide.htm

http://www.quia.com/mc/11125.html

http://www.vectorkids.com/vkdivisible.htm

http://www.funtrivia.com/playquiz/quiz2534921d05d68.html

http://www.studystack.com/menu-57154

http://www.lifesmith.com/mathfun.html#anchor613541

http://www.math6.org/fraction_ready/divisibility_rules/divisibility_rules.htm

http://mathforum.org/dr.math/faq/faq.divisibility.html