static void Main(string[] args) { Calculadora calc = new Calculadora(); string[] arquivosTeste = { "x1"}; // , "x2", "x3", "x4", "x5", "x6", "x7", "x8" foreach (string arq in arquivosTeste) { using (StreamReader reader = new StreamReader("C:\\Users\\Andressa\\Documents\\Visual Studio 2015\\Projects\\CalculadoraJB\\CalculadoraJB\\"+arq)) { string linha; while ((linha = reader.ReadLine()) != null) { calc.Input(linha); } //using (StreamReader reader2 = new StreamReader("C:\\Users\\Andressa\\Documents\\Visual Studio 2015\\Projects\\CalculadoraJB\\CalculadoraJB\\resultado"+arq)) //{ //} } } Console.ReadLine(); }