Noob question: Value from class

I want to do create a class that rounds off a decimal. I’m running into problems and I assume the solution is pretty simple but I’m not finding an answer in the books I have nor in searches.

Here’s what I have:

package {
 public class Round {
  private var _num:Number;
  private var _int:int;
  private var _decimal:Number;
  public function Round(num:Number):Number {
   _num = num;
   _int = int(_num);
   _decimal = _num - _int;
   if (_decimal >= 0.5) {
    return _int + 1;
   } else {
    return _int;

First of all, I know that you can’t have a constructor return a value, but I have tried to simply reassign the code to a non-constructor function and still cannot make this work.

Again, I’m sure it’s simple but I’m just not well-versed enough in AS3. How do I make my class return a simple value, so that I can call, for example, Round(2.355) and get 2?