How to create methods in java

class Main{

public void sum(){

int i=5;

int j=6;

int s=i+j;

System.out.println("Sum of the two numbers : "+s);

}

public void mult(int a, int b){

int c;

int d;

c=a;

d=b;

int mult=c*d;

System.out.println("Multiplication of two numbers : "+mult);

}

public static void main(String args[]){

Main obj1=new Main();

Main obj2=new Main();

obj1.sum();

obj2.mult(5,4);

}

}

OUTPUT:- 

C:\Users\Satyendra\Desktop>javac 1.java

C:\Users\Satyendra\Desktop>java Main

Sum of the two numbers : 11

Multiplication of two numbers : 20