Art of Problem Solving
AoPS Online
Math texts, online classes, and more
for students in grades 5-12.
Visit AoPS Online ‚
Books for Grades 5-12 Online Courses
Beast Academy
Engaging math books and online learning
for students ages 6-13.
Visit Beast Academy ‚
Books for Ages 6-13 Beast Academy Online
AoPS Academy
Small live classes for advanced math
and language arts learners in grades 2-12.
Visit AoPS Academy ‚
Find a Physical Campus Visit the Virtual Campus

Divisibility rules/Rule for 19 proof

Revision as of 13:19, 22 August 2006 by JBL (talk | contribs)

If $k=d_110^0+d_210^1+d_310^2+...$, we can say that $k+2d_0\equiv 20k+2d_0\equiv 10k+d_0$, which is our original number.


Back to Divisibility Rules

Retrieved from "https://artofproblemsolving.com/wiki/index.php?title=Divisibility_rules/Rule_for_19_proof&oldid=9765"