Summary
More on the divisible by 3 rule:
A number is divisible by 3 if the sum of the digits is divisible by 3. e.g
Example: 492
Step 1: Add up the digits. 4 + 9 + 2 = 15
Step 2: Determine if 3 divides evenly into the sum of 15. Yes, 3 x 5 = 15. So 3 goes evenly into 15.
So 3 is a factor of 34,911. i.e. 492/3 = 164
Example: 34,911
Step 1: Add up the digits. 3 + 4 + 9 + 1 + 1 = 18
Step 2: Determine if 3 divides evenly into the sum of 18. Yes, 3 x 6 = 18. So 3 goes evenly into 18. So 3 is a factor of 34,911. i.e. 34,911/3 = 11,637