step 6

Step 6: Create the client application as shown below and add the reference 'System.ServiceModel', this is the core dll for WCF.
Step 8: Add the proxy class and configuration file to the client application. Create the object for the MathServiceClient and call the method.
Program.cs

 class Program
    {
        static void Main(string[] args)
        {
            MathServiceClient client = new MathServiceClient();
            Console.WriteLine("Sum of two number 5,6");
            Console.WriteLine(client.Add(5,6));
            Console.ReadLine();

        }
    }

The output will be shown as below.