C++

Program for making a Simple Calculator..........

#include<iostream.h>
#include<conio.h>
#include<math.h>
void main()
{
clrscr();
int a,b,op;
float long ans;
cout<<"\t\t WELCOME TO CALCULATOR PROGRAM........"<<endl;
cout<<"A PROGRAM by \n\t\t HAKIM VOHRA"<<endl;
cout<<"1) ADDITION(+) \n2) SUBTRACTION(-) \n3) MULIPLICATION(*) \n4) DIVISION(/) \n5) SQUARE(^2) \n6) CUBE(^3)"<<endl;
cout<<"Select the operation you would like to do: "<<endl;
cin>>op;
switch(op)
{
case 1:
 cout<<"Enter the values.."<<endl;
 cout<<"a: ";
 cin>>a;
 cout<<"b: ";
 cin>>b;
 ans= a + b;
 cout<<"ADDITION : "<<ans<<endl;
break;
case 2:
 cout<<"Enter the values.."<<endl;
 cout<<"a: ";
 cin>>a;
 cout<<"b: ";
 cin>>b;
 ans= a - b;
 cout<<"SUBTRACTION : "<<ans<<endl;
break;
case 3:
 cout<<"Enter the values.."<<endl;
 cout<<"a: ";
 cin>>a;
 cout<<"b: ";
 cin>>b;
 ans= a * b;
 cout<<"MULTIPLICATION : "<<ans<<endl;
break;
case 4:
 cout<<"Enter the values.."<<endl;
 cout<<"a: ";
 cin>>a;
 cout<<"b: ";
 cin>>b;
 if((b<0)||(b>0))
 {
  ans=a/b;
 }
 else
 {
  cout<<"MATHEMATICAL ERROR";
 }
 cout<<"DIVISION: "<<ans<<endl;
break;
case 5:
 cout<<"Enter the number whose square you want.."<<endl;
 cout<<"a: ";
 cin>>a;
 ans= a*a;
 cout<<"SQUARE : "<<ans<<endl;
break;
case 6:
 cout<<"Enter the number whose cube you want.."<<endl;
 cout<<"a: ";
 cin>>a;
 ans= a*a*a;
 cout<<"CUBE : "<<ans<<endl;
break;
default:
cout<<"INVALID OPTION";
}
getch();
}