unable to get percentage in decimal values ?

Question

Hie friends

I Have written this code in note pad i am trying to pass values via command prompt i.e 

after compiling : csc cmdparams.cs then after 

 i am passing cmdparams 70 75 64 58 79 83 73 50

using System;

class cmdparams

{

    static void Main(string[] args)

    {

        int sum = 0;

       double per = 0;

        foreach (string str in args)

            sum += int.Parse(str);

        per = Convert.ToInt32(sum * 100 / 750);

        Console.WriteLine("sum is {0}", sum);

        Console.WriteLine("percentage is {0}", per);

        Console.ReadLine();

    }

}

problem here is when i calculate percentage i am getting round figure like 73 but in reality its 73.6 .. 

-->> Here i want to display output in cmd-prompt with decimals ??

Is there any way ?

Thank you