SOLUTION: A WHOLE NUMBER IS DIVISIBLE BY 3, IF IT'S SUM IS DIVISIBLE BY 3..NOT SURE HOW TO DO THIS PLEASE HELP..

Question 29768: A WHOLE NUMBER IS DIVISIBLE BY 3, IF IT'S SUM IS DIVISIBLE BY 3..NOT SURE HOW TO DO THIS PLEASE HELP..
Answer by Cintchr(481) (Show Source): You can put this solution on YOUR website!
This rule works for dividing by nine as well.
take the number 345. Add the digits up.
3 + 4 + 5 = 12
look at the answer ... 12. 12 is divisible by 3, so the number 345 is as well.
take a HUGE number .... 34,826,406,723,467
add the digits ...
3+4+8+2+6+4+0+6+7+2+3+4+6+7=62
we can now take 62 ... 6 + 2 = 8 .
3 can not go into 8 ... so it can not go into 34,826,406,723,467.
The same holds true with the number 9. but the sum of the numbers has to be divisible by 9.
85,716
8+5+7+1+6=27
9 goes into 27, so it goes into 85,716
RELATED QUESTIONS
A whole number is divisible by 3 if the sum of its digits is divisible by... (answered by Earlsdon)

One example of counterexample: If a whole number is divisible by 2, it is also divisible... (answered by KMST)

If a number is divisible by 2 and 3, it must also be divisible by 6. a. True (answered by checkley71)

it is a 4 digit whole number each of its digits are divisible by 3 it is divisible by 4... (answered by erica65404)

Classify each of the following as true or false: (a) If a number is divisible by 6, then (answered by richwmiller)

if the sum of the digits of a 3 digit number is divisible by 9, prove that the 3 digit... (answered by ikleyn)

The objective of the puzzle is to discover the number given the clues below. It is a... (answered by ikleyn,greenestamps)

We know that for a number to be divisible by 3, we have to add up the individual digits... (answered by jim_thompson5910)

If a number is divisible by 8, then it is also divisible by 16. Is this true or false?... (answered by richwmiller)

Classify each of the following as True or False a.If a number is divisible by 4 and 6... (answered by Deina)