Question: is 12 divisible by 3?
Answer: Now, we are going to check if it is divisible by 3 by adding all the digits, 1 + 3 + 8 = 12. As 12 is divisible by 3, then 138 is also divisible by 3. Since 138 is divisible by both 3 and 2, 138 it is also divisible by 6.