en.wikipedia.org/wiki/Divisibility_rule

Note: To test divisibility by any number that can be ... For example, testing
divisibility by 24 (24 = 8*3 ...

www.aaamath.com/div66_x3.htm

Numbers are divisible by 3 if the sum of all the individual digits is evenly divisible
by 3. For example, the sum of the digits for the number 3627 is 18, which is ...

www.counton.org/explorer/primes/divisibility-by-3/

To see if a number is exactly divisible by 3 just add up all its digits. If that sum is
divisible by 3, then so is the original number. For example: is 2000 a multiple of ...

www.softschools.com/math/topics/the_divisibility_rules_3_6_9/

The Divisibility Rules: 3, 6, 9. Have you ever wondered why some numbers will
divide evenly (without a remainder) into a number, while others will not?

www.khanacademy.org/math/in-sixth-grade-math/playing-numbers/test-divisibility-numbers/v/the-why-of-the-3-divisibility-rule

Why you can add the digits to see if something is divisible by 3. ... 3: Playing with
numbers|. Test for divisibility of numbers ... Divisibility tests for 2, 3, 4, 5, 6, 9, 10.

www.khanacademy.org/math/pre-algebra/pre-algebra-factors-multiples/pre-algebra-divisibility-tests/v/the-why-of-the-3-divisibility-rule

It will only work with numbers that are factors of 9 (i.e. 3 and 9). The reason is that
every time you go above 10, you increase the value in the tens column by 1, ...

www.virtualnerd.com/pre-algebra/factors-fractions-exponents/divisibility/divisibility-definition-rules/simple-divisibility-tests

You'll learn some neat rules for figuring out if a number is divisible by 2, 3, 5, 6, ...
definition; rule; rules; divisibility; divisible; divisibility rules; divide; divide by 2 ...

www.math10.com/en/algebra/divisibility/divisibility-by-3-9.html

Divisibility by 3 and 9. Divisibility by 9. All numbers that contain only the digit 9
are divisible by 9. For example: 9, 99, 999, 99999. Lets us take a number, ...

www.montereyinstitute.org/courses/DevelopmentalMath/COURSE_TEXT_RESOURCE/U02_L1_T3_text_final.html

Factors and Primes. Learning Objective(s). · Recognize (by using the divisibility
rule) if a number is divisible by 2, 3, 4, 5, 6, 9, or 10. · Find the factors of a number
...

mathforum.org/k12/mathtips/division.tips.html

From: Dr. Math To: Kevin Gallagher Subject: Re: Divisibility of a number by 3 As
Kevin Gallagher wrote to Dr. Math On 5/11/96 at 21:35:40 (Eastern Time), >I'm ...