#include <stdio.h>
#include <conio.h>
#include <process.h>
void main ()
{
    int a, b, c, choice;
    clrscr ();
    printf ("\t\t\t\t ** Calculation Program ** ");
    printf ("\n\n\n\nEnter First Value: ");
    scanf ("%d", &a);
    printf ("\n\nEnter Second Value: ");
    scanf ("%d", &b);
    printf ("\n\n\t1. Addition");
    printf ("\n\n\t2. Subtraction");
    printf ("\n\n\t3. Multiplication");
    printf ("\n\n\t4. Divide");
    printf("\n\n\t5. Exit");
    printf ("\n\n\nSelect Your Choice: ");
    scanf ("%d", &choice);
    switch (choice)
    {
        case 1:
            c = a + b;
            break;
        case 2:
            c = a - b;
            break;
        case 3:
            c = a * b;
            break;
        case 4:
            c = (float)a / b;
            break;
        case 5:
            printf ("\n\nThank Your For Using This Program");
            getch ();
            exit (0);
        }
        if(choice>=6)
        {
            printf("\n\nInvalid Key!!!");
            printf("\n\n\nTry Again Later.");
            getch ();
            exit (0);
        }

    printf ("\n\nResult = %d", c);
    printf ("\n\n\nThank You!!!!!");
    getch ();
}

#include <stdio.h>
#include <conio.h>
void main()
{
    clrscr ();
    float a, b, c;
    char choice;
    printf("Enter the first number");
    scanf("%f",&a);
    printf("Enter the second number");
    scanf("%f",&b);
    printf("Enter Your Operator: ");
    scanf ("%c", &choice);
if (choice == '+')
{
    c = a + b;
}
else if (choice =='-')
{
    c = a - b;
}
else if (choice =='*')
{
    c = a * b;
}
else if (choice =='/')
{
    c = (float)a / b;
}
else
    c = 0;

    printf("Result = %.2f", c);
}