sum of numbers in java

1import java.util.Scanner;
2public class SumDigit {
3    public static void main(String[] argh){
4        System.out.println("Enter int");
5        Scanner input = new Scanner(System.in);
6        int n = input.nextInt();
7        int sum = 0 ;
8        int i = 0;
9        print( i =Sum_of_digits(sum,n));
10    }
11
12    public static int Sum_of_digits(int sum,int n){
13        if(n<=0)
14            return sum ;
15        sum += n%10;
16        return Sum_of_digits(sum,n/10);
17    }
18
19    public static void  print(int n){
20        System.out.print(n);
21    }
22}

1import java.io.*;
2public class sd
3{
4  public static void main(String [] args)throws IOException
5  {
6     InputStreamReader hi = new InputStreamReader(System.in);
7        BufferedReader in = new BufferedReader(hi);
8        System.out.println("Enter the number");
9        int num=Integer.parseInt(in.readLine());
10    int sum=0;
11    while(num>=0)
12    {
13      int rem=n;
14      sum+=rem;
15      int quo=n/10;
16      n=quo;
17    }
18    System.out.println(sum);
19  }
20}

1import java.util.Scanner;
2
3public class Main {
4
5    public static void main(String[] args) {
6
7        Scanner scanner = new Scanner(System.in);
8
9        System.out.print("Enter two numbers: ");
10        int num1 = scanner.nextInt() , num2 = scanner.nextInt();
11
12        int sum = num1 + num2 ;
13        System.out.printf("The sum of %d and %d is %d",num1, num2, sum);
14    }
15}

1static void M1(int num1, int num2) {
2        int sum = num1 + num2;
3        System.out.println("sum of " + num1 + " and " + num2+ " = " + sum);    
4    }
5 
6    public static void main(String[] args) {
7        // using Methods
8        Scanner input = new Scanner(System.in);
9        int num1,num2;
10        System.out.println("Enter a number: ");
11        num1 =input.nextInt();
12        System.out.println("Enter 2nd number: ");
13        num2 =input.nextInt();
14        input.close();
15        M1(num1, num2);
16    }
17}

1public class SumNatural {
2
3    public static void main(String[] args) {
4
5        int num = 100, sum = 0;
6
7        for(int i = 1; i <= num; ++i)
8        {
9            // sum = sum + i;
10            sum += i;
11        }
12
13        System.out.println("Sum = " + sum);
14    }
15}