diff --git a/64_Nicomachus/csharp/program.cs b/64_Nicomachus/csharp/program.cs
new file mode 100644
index 00000000..c8ba4184
--- /dev/null
+++ b/64_Nicomachus/csharp/program.cs
@@ -0,0 +1,122 @@
+using System.Text;
+using System.Threading;
+
+namespace Nicomachus
+{
+    class Nicomachus
+    {
+        private void DisplayIntro()
+        {
+            Console.WriteLine();
+            Console.WriteLine("NICOMA".PadLeft(23));
+            Console.WriteLine("CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY");
+            Console.WriteLine();
+            Console.WriteLine();
+            Console.WriteLine();
+            Console.WriteLine("Boomerang puzzle from Arithmetica of Nicomachus -- A.D. 90!");
+       }
+
+        private bool PromptYesNo(string Prompt)
+        {
+            bool Success = false;
+
+            while (!Success)
+            {
+                Console.Write(Prompt);
+                string LineInput = Console.ReadLine().Trim().ToLower();
+
+                if (LineInput.Equals("yes"))
+                    return true;
+                else if (LineInput.Equals("no"))
+                    return false;
+                else
+                    Console.WriteLine("Eh?  I don't understand '{0}'  Try 'Yes' or 'No'.", LineInput);
+            }
+
+            return false;
+        }
+
+        private int PromptForNumber(string Prompt)
+        {
+            bool InputSuccess = false;
+            int ReturnResult = 0;
+
+            while (!InputSuccess)
+            {
+                Console.Write(Prompt);
+                string Input = Console.ReadLine().Trim();
+                InputSuccess = int.TryParse(Input, out ReturnResult);
+                if (!InputSuccess)
+                    Console.WriteLine("*** Please enter a valid number ***");
+            }   
+
+            return ReturnResult;
+        }
+
+        private void PlayOneRound()
+        {
+            Random rand = new Random();
+            int A_Number = 0;
+            int B_Number = 0;
+            int C_Number = 0;
+            int D_Number = 0;
+
+            Console.WriteLine();
+            Console.WriteLine("Please think of a number between 1 and 100.");
+
+            A_Number = PromptForNumber("Your number divided by 3 has a remainder of? ");
+            B_Number = PromptForNumber("Your number divided by 5 has a remainder of? ");
+            C_Number = PromptForNumber("Your number divided by 7 has a remainder of? ");
+
+            Console.WriteLine();
+            Console.WriteLine("Let me think a moment...");
+
+            Thread.Sleep(2000);
+
+            D_Number = 70 * A_Number + 21 * B_Number + 15 * C_Number;
+
+            while (D_Number > 105)
+            {
+                D_Number -= 105;
+            }
+
+            if (PromptYesNo("Your number was " + D_Number.ToString() + ", right? "))
+            {
+                Console.WriteLine();
+                Console.WriteLine("How about that!!");
+            }
+            else
+            {
+                Console.WriteLine();
+                Console.WriteLine("I feel your arithmetic is in error.");
+            }
+
+            Console.WriteLine();
+
+       }
+
+        public void Play()
+        {
+            bool ContinuePlay = true;
+
+            DisplayIntro();
+
+            do 
+            {
+                PlayOneRound();
+
+                ContinuePlay = PromptYesNo("Let's try another? ");
+            }
+            while (ContinuePlay);
+        }
+    }
+    class Program
+    {
+        static void Main(string[] args)
+        {
+
+            new Nicomachus().Play();
+
+        }
+    }
+}
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