Divisibilty rule for 3
To find if a number is divisible by 3 you have to see if the sum of the numbers is divisible by 3.
Eg: 1236. 1+2+3+6=12
if you don't know if 12 is divisible by 3, add up the 2 digits. 1+2=3
1236 is divisible by 3.
Let's try this. 1467523
If your not sure if it's divisible by 3 or not, add the 2 digits.
1 is not divisible by 3
Try this question in the comments.
983142. Is it divisible by 3?
The other divisiblity rules are either posted or are being posted soon by other people. Make sure you check those out.