1  static void Main(string[] args)
 2         {
 3             /*This is a comment*/
 4             /*And so...
 5                        ...is this!*/
 6             //This is a different sort of comment.
 7             // <A statement>; //Explanation of statement
 8             /*#region Using directives
 9             using System;
10             using System.Collections.Generic;
11             using System.Linq;
12             using System.Text;
13             using System.Threading.Tasks;
14             #endregion*/
15              //使用简单类型变量
16              /*int myInteger;
17              string myString;
18              myInteger=17;
19              myString="\"myInteger\" is ";//转义序列\转义双引号
20              //myString = "This string has a\nline break.";
21              //myString = @"C:\Temp\MyDir\MyFile.doc";
22              Console.WriteLine("{0}{1}.", myString, myInteger);
23              Console.ReadKey();
24              //@"C:\Temp\MyDir\MyFile.doc"*/
25             //变量的声明和赋值
26             int xSize = 4 , ySize = 5 , zSize = 6 , aSize = 7 ;
27             xSize = ySize++ * --zSize;
28             Console.WriteLine("{0}{1}{2}{3}", xSize, ySize, zSize, aSize);
29             Console.ReadKey();
30
31
32
33         }

减去; 减，扣除，做减法( subtract的现在分词 );

ex:the result of subtracting a from b is c;||

||sum[英][sʌm][美][sʌm]
n.总数; 算术; 金额; 概略，要点; 
vt.& vi.总计; 总结，概括; 归纳;

ex: the sum of a and b is c;||

||

ex:the product of a and b is c;||

||dividing by 除法

 1 static void Main(string[] args)
 2         {
 3             //变量赋值、用户输入、类型转换、加减乘除余数
 4             /*double firstNumber, secondNumber;
 5             string userName;
 6             Console.WriteLine("Enter your name:");
 7             userName = Console.ReadLine();
 8             Console.WriteLine("Welcome {0} !", userName);
 9             Console.WriteLine("Now give me a number :");
10             firstNumber=Convert.ToDouble(Console.ReadLine());
11             Console.WriteLine("Now give me another number :");
12             secondNumber = Convert.ToDouble(Console.ReadLine());
13             Console.WriteLine("The sum of {0} and {1} is {2}.", firstNumber, secondNumber, firstNumber + secondNumber);
14             Console.WriteLine("The result of subtracting {0} from {1} is {2}.", secondNumber, firstNumber, firstNumber - secondNumber);
15             Console.WriteLine("The product of {0} and {1} is {2}.", firstNumber,secondNumber,firstNumber * secondNumber);
16             Console.WriteLine("The result of dividing {0} by {1} is {2}.", firstNumber, secondNumber, firstNumber / secondNumber);
17             Console.WriteLine("The remainder after dividing {0} by {1} is {2}.", firstNumber, secondNumber, firstNumber % secondNumber);
18             Console.ReadLine();*/
19             int firstNumber, secondNumber, thirdNumber, fourthNumber;
20             Console.WriteLine("Give me a number :");
21             firstNumber = Convert.ToInt32(Console.ReadLine());
22             Console.WriteLine("Give me another number :");
23             secondNumber = Convert.ToInt32(Console.ReadLine());
24             Console.WriteLine("Give me another number :");
25             thirdNumber = Convert.ToInt32(Console.ReadLine());
26             Console.WriteLine("Give me another number :");
27             fourthNumber = Convert.ToInt32(Console.ReadLine());
28             Console.WriteLine("The product of {0}, {1}, {2}, and {3} is {4}.", firstNumber, secondNumber, thirdNumber, fourthNumber, firstNumber * secondNumber * thirdNumber * fourthNumber);
29             Console.ReadLine();
30
31         }