static void Main(string[] args) { Calculator _calc = new Calculator(); string userInput= ""; while (userInput != "exit") { Console.WriteLine("Enter a calculation below, you can use [] for bodmas e.g. [3 + 5] x 2"); userInput = Console.ReadLine(); double result; if (_calc.ContainsBrackets(userInput)) { var opertionWithBracketsCalculated = _calc.BracketIsolationCalculation(userInput); result = _calc.GetResultFromSingleCalculation(opertionWithBracketsCalculated); } else { result = _calc.GetResultFromSingleCalculation(userInput); } Console.WriteLine(result); //Console.WriteLine("Press enter to clear"); //Console.Read(); //Console.Clear(); } }