WebService Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{

This is code from my Consumer app. It doesn't like "local host" - could not be found. Can you help?

    class Program
    {
        static void Main(string[] args)
        {
            localhost.Service1 myMathService = new localhost.Service1();
            Console.Write("2 + 4 = {0}", myMathService.Add(2, 4));
        }
    }
}
*************************************************** Producer ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;

namespace MathService
{
    /// <summary>
    /// Summary description for WebService1
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
    // [System.Web.Script.Services.ScriptService]
    public class WebService1 : System.Web.Services.WebService
    {

        [WebMethod]
        public int Add(int a, int b)
        {
            return (a + b);
        }

        [WebMethod]
        public System.Single Subtract(System.Single A, System.Single B)
        {
            return (A - B);
        }

        [WebMethod]
        public System.Single Multiply(System.Single A, System.Single B)
        {
            return A * B;
        }

        [WebMethod]
        public System.Single Divide(System.Single A, System.Single B)
        {
            if (B == 0)
                return -1;
            return Convert.ToSingle(A / B);
        }
    
    }
}