Need Help! Define a Multiply Function

using System;

class Program
{
    static double Multiply(double firstParameter, double secondParameter)
    {
    return firstParameter * secondParameter;
    }
    // YOUR CODE HERE: Define a method named Multiply. Remember
    // to use the "static" and "void" keywords: "static void
    // Multiply" (without quotes). Multiply should take two
    // "double" values as parameters.

    static void Main(string[] args)
    {
        double firstParameter = Multiply(2.5, 2);
        Console.WriteLine(firstParameter);
        double secondParameter = Multiply(6, 7);
        Console.WriteLine(secondParameter);
    }

}