C#

using System;

namespace _11.MathOperations
{
    internal class Program
    {
        static void Main(string[] args)
        {
            double numberOne = double.Parse(Console.ReadLine());

            char calculationType = char.Parse(Console.ReadLine());

            double numberTwo = double.Parse(Console.ReadLine());

            CalculationType(numberOne, calculationType, numberTwo);
        }

        static void CalculationType(double numberOne, char calculationType, double numberTwo)
        {
            if (calculationType == '+')
            {
                double result = numberOne + numberTwo;
                Console.WriteLine(result);
            }

            else if (calculationType == '-')
            {
                double result = numberTwo - numberOne;
                Console.WriteLine(result);
            }

            else if (calculationType == '*')
            {
                double result = numberOne * numberTwo;
                Console.WriteLine(result);
            }

            else if (calculationType == '/')
            {
                double result = numberOne / numberTwo;
                Console.WriteLine(result);
            }
        }
    }
}