C++ ile Dört İşlem Yapan Bir Hesap Makinesi Yapmak

#include <cstdlib>
#include <iostream>

using namespace std;

int main(int argc,char *argv[])
{
    cout<<"*************************************"<<endl;
    cout<<"*         HESAP MAKINESI            *"<<endl;
    cout<<"*        TOPLAMA ICIN [+]           *"<<endl;
    cout<<"*        CIKARMA ICIN [-]           *"<<endl;
    cout<<"*        BOLME   ICIN [/]           *"<<endl;
    cout<<"*        CARPMA ICIN            *"<<endl;    cout<<"*   Islemlerini Kullaniniz          *"<<endl;
    cout<<"*        Sanalkurs.net              *"<<endl;
    cout<<"*************************************"<<endl;
    system("color F0");
    float sayi1,sayi2,sonuc;
    char islem;
    cout<<"1.sayiyi giriniz :";
    cin>>sayi1;
    
    cout<<"islemi giriniz :";
    cin>>islem;
    
    cout<<"1.sayiyi giriniz :";
    cin>>sayi2;
    
    switch(islem)
    {
       case '+':
            sonuc = (sayi1+sayi2);
            cout<<"Toplama Sonucu :"<<sonuc<<endl; break;
            
        case '-':
            sonuc = (sayi1-sayi2);
            cout<<"Cıkarma Sonucu :"<<sonuc<<endl; break;
        
        case '*':
            sonuc = (sayi1*sayi2);
            cout<<"Carpma Sonucu :"<<sonuc<<endl; break;   
        
          case '/':
            sonuc = (sayi1/sayi2);
            cout<<"Bolme Sonucu :"<<sonuc<<endl; break;
                    
                 }
    
    system("PAUSE");
    return EXIT_SUCCESS;
}