okay. the best way to do this is to first change it to a fraction, and then think of how you would say it. so, when changing a decimal to a fraction, look at the right most number. 6 is in this case. what place is it in? 6 is in the thousandths place. (if this doesn't make sense to you we can go over it seperately). whatever place that number is in, THAT'S your denominator. so I have:
some number
---------------------
1000
what's that "some number"? well, going from left to right, and ignoring the decimal, I have 306, right? this number is your numerator, or top value. so now I have....
306
-------
1000
alroght! so how would you say that? personally, I would say:
three-hundred and six thousandths. this would be in word form. hope that helps!