How can you find if a number is divisible by 3?

Question

I know theres an equation, I just dont know the equation.

Answer 1

If the sum of the digits is divisible by three, the number is also

Answer 2

All numbers are divisible by all numbers, except by 0, you just wont always get a whole number. To see if a number is divisible by 3, you need to know the 3 times table. So if you want to see if 99 is divisible by 3, then you do that times table thing: 3x1=3, 3x2=6, 3x3=9, 3x4=12, and so on until you get to 3x33=99. Of course, you won't go through the whole process of the times table, you should already know the times table by heart. The school way is to factorize the numbers, or break them down by the numbers that are multiplied to make up the number in question.

Answer 3

Add up the digits of the number, if the sum of the digits is divisible by six , so is the number
for example
lets take 321
adding up the digits 3+2+1=6
6 is a multiple of 3
so 321 is also divisible by 3

Answer 4

add up the digits ex. 27= 2+7=9 9 is divisible by 3

Answer 5

i think if it is divisible by 9 or 6 it is divisible by 3. but i learned that a long time ago so i might be wrong