Competition Math

Divisibility Tricks

This video covers some basic divisibility tricks with 1, 2, 3, 4, and 5. Learn how to tell if a number is divisible by any of those 5 numbers.

This video, similar to the last one, contains divisibility tricks and tips for the numbers 6 through 11. The rules for 7 and 11 are tricky; be sure to practice these so they come naturally during a contest.