Methods improvements
You should aim to declare variables at initialization when possible. Pre-initialized variables are suspicious and make me wonder whether they are being optionally assigned or edited elsewhere.
       // string userAnswer;

       Console.WriteLine(&quot;Calculater or Square Root Calculater?&quot;);
       Console.WriteLine(&quot;-Please respond with Calculater or Square&quot;);
       string userAnswer = Console.ReadLine().ToUpper();
       Console.Clear();