public static void Main()
Console.WriteLine("*** PHEP TOAN CO BAN ***");
Console.WriteLine("Nhap so nguyen a: ");
int a = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Nhap so nguyen b: ");
int b = Convert.ToInt32(Console.ReadLine());
double chiaThapPhan = a / b;
Console.WriteLine($"{a} + {b} = {cong}");
Console.WriteLine($"{a} - {b} = {tru}");
Console.WriteLine($"{a} * {b} = {nhan}");
Console.WriteLine($"{a} / {b} = {chiaNguyen} - chia nguyen");
Console.WriteLine($"{a} / {b} = {chiaThapPhan:0.00} - chia thap phan");
Console.WriteLine($"{a} % {b} = {chiaDu}");