Program To Input Two Number From User And Calculate Add,Sum,Multi,and Div Of The Number According To The Choice

/*program of menu driven program*/
# include <stdio.h>
void main ()
{
int a,b,c,choice ;
clrscr () ;
printf ("/n enter the first number :") ;
scanf ("%d", & a) ;
printf ("/n enter second number :");
scanf ("%d", & b) ;
printf ("/n you can perform the following operation :") ;
printf ("/n 1.addition :") ;
printf ("/n 2.subtraction :") ;
printf ("/n 3. multiplication :") ;
printf ("/n 4. division :") ;
printf ("/n enter your choice :") ;
scanf ("%d", & choice) ;
switch (choice)
{
case 1 ;
c= a+b ;
printf ("/n sum = %d", c) ;
break ;
case 2 ;
c= a-b ;
printf ("/n sub = %d", c) ;
break ;
case 3 ;
c= a*b ;
printf ("/n multi = %d", c) ;
break ;
case 4 ;
c= a\b ;
printf ("/n div = %d". c) ;
break ;
default :
printf ("/n invalid number :") ;
}
getch () ;
}