基础：类型转换

1             //测试三
2             int a = 701;
3             int b = 7;
4             double r1 = (double)a / b;
5             decimal r2 = (decimal)a / b;
6             decimal d = System.Decimal.Round(r2, 2);//保留2位小数
7             Console.WriteLine(r1);
8             Console.WriteLine(r2);
9             Console.WriteLine(d);