Scintific Calculator (console app) you can add more function's :-)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace scintificCalculator
{
    class Program
    {
        static void Main(string[] args)
        {
            int value,number;
            Console.WriteLine("Scintific Calculator");
            Console.WriteLine("Enter your chioce");
            Console.WriteLine("1. sin");
            Console.WriteLine("2. cos");
            Console.WriteLine("3. tan");
            Console.WriteLine("4. x!");
            Console.WriteLine("5. sinh");
            Console.WriteLine("6. x^y ");
            value = Int32.Parse(Console.ReadLine());
           
            switch (value)
            {
                case 1:
                  
                    double a, value1;
                    int number8;
                    Console.WriteLine("enter the theta value");
                    number8 = Int32.Parse(Console.ReadLine());
                    a = 180 - number8;
                    value1 = (4 * number8*a) / (40500-(number8*a));
                    Console.WriteLine("" + value1 );
                    break;

                case 2:
                    double value2,number1;
                   Console.WriteLine("enter the theta value");
            number1 = Int32.Parse(Console.ReadLine());
                    value2 = Math.Cos(number1* (Math.PI / 180));
                    Console.WriteLine("cos value is " + value2);
                    break;
                case 3:
                    double tanval,number2;
                    Console.WriteLine("enter the theta value");
            number2 = Int32.Parse(Console.ReadLine());
                    tanval = Math.Tan(number2 * (Math.PI / 180));
           
                    Console.WriteLine("cos value is " + tanval);
                    break;

                case 4:
                    int i, fact = 1,number3;
                    Console.WriteLine("enter the value");
            number3 = Int32.Parse(Console.ReadLine());
                       
         
            for (i = 1; i <=number3; i++)
            {
                fact = fact * i;
            }

            Console.WriteLine("factorial of number is " + fact);
            break;
           
                case 5:
            double sinhval,number4;
                    Console.WriteLine("enter the theta value");
            number4 = Int32.Parse(Console.ReadLine());


                    sinhval = Math.Sinh(number4 * (Math.PI / 180));
                    Console.WriteLine("cos value is " + sinhval);

            break;
                case 6:
                   
            int number7, power,j;
            double value7=1;
            Console.WriteLine("enter the number");
            number7 = Int32.Parse(Console.ReadLine());
            Console.WriteLine("enter the power value ");
            power = Int32.Parse(Console.ReadLine());
            for (j = 0; j <power ;j++ )
            {
                value7 = value7* number7;
              
               
            }
            Console.WriteLine("final result is " + value7);
       
                    break;

            }
        }
    }
}