Switch - Case

//Write a program to design calculator in C

#include<stdio.h>
#include<conio.h>
void main()
{
 int ch,n1,n2,r;
 printf("1 Addition\n2 Subtraction\n3 Multiplication\n4 Division\n");

 printf("Enter your choice");
 scanf("%d",&ch);

 printf("Enter first value ");
 scanf("%d",&n1);

 printf("Enter second value ");
 scanf("%d",&n2);

 switch(ch)
 {
  case 1:
   r=n1+n2;
   printf("Addition of first and second value is %d",r);
   break;
  case 2:
   r=n1-n2;
   printf("Subtraction of first and second value is %d",r);
   break;
  case 3:
   r=n1*n2;
   printf("Multiplication of first and second value is %d",r);
   break;
  case 4:
   r=n1/n2;
   printf("Division of first and second value is %d",r);
   break;

 default:
 printf("Out of option");

 }

getch();
}