Is a number has a 9 in the ones place it is always divisible by 3?

No, a number with a 9 in the ones place is not always divisible by 3. For a number to be divisible by 3, the sum of its digits must be divisible by 3, regardless of the digit in the ones place. For example, the number 29 has a 9 in the ones place, but its digit sum (2 + 9 = 11) is not divisible by 3.