Can you make this equation true?

Logic Level 2

$\LARGE 9 \ \ \ \ \ 9 \ \ \ \ \ 9 \ \ \ \ \ 9 \ \ = \ \ 100$

What is the fewest number of operators $(+, -, \times, \div)$ needed on the left hand side of the equation to make the statement true?

Details and Assumptions:

For example, if the equation $9 + 9 + 9 \div{9}= 100$ is true, then you have used 3 operators: one division and two additions.
You are allowed to concatenate the digits, but it does not count as an operation. (That is, you can treat 9 9 as 99.)