How many positive 3-digit integers can be formed using the digits 0, 1, 2, 3, 4, and 5? My Question says, Using the digits (0, 1, 2, 3, 4, 5), how many positive 3-digit integers can be formed?

So my work so far is for positive 3 digit integers you would have the choice of 6 digits for the first digit, the choice of 6 digits for the second digit, and the choice of 6 digits for the third digit: (6)(6)(6) 

But I'm not sure where to go from here, do I simply multiply them together? Is there another step afterwards? Am I missing something? Please help!
The first digit cannot be $0$. Therefore the answer is $5\times6^2$.
The first digit cannot be $0$. Therefore the answer is $5\times6^2$.