static void Main(string[] args)
        {
            int sayi1 = 12;
            int sayi2 = 10;
            int sayi3 = 5;
            int sayi4 = 2;

            DortIslem dortIslem = new DortIslem();

            dortIslem.toplama(sayi1, sayi2);
            dortIslem.cikarma(sayi2, sayi3);
            dortIslem.carpma(sayi3, sayi4);
            dortIslem.bolme(sayi2, sayi4);
        }