1. 평균값 구하기

import java.util.Scanner;
public class AverageOfThree {
    public static void avg(int num1, int num2, int num3) {
        System.out.println((num1 + num2+ num3)/3);
    }
    public static void main(String[] args)
    {int num1,num2,num3;
    double average;
    Scanner scan = new Scanner(System.in);
  
   
     System.out.println("Enter the first number: ");  
     num1=scan.nextInt();
     System.out.println("Enter the second number: ");
     num2=scan.nextInt();
     System.out.println("Enter the third number: ");
     num3=scan.nextInt();
     avg(num1, num2, num3);
             }
    
}
2. 계산기
import java.util.Scanner;

public class FloatCalculations
{
  public static void sum(float num1, float num2) {
      System.out.println(num1 + num2);
  }
    public static void difference(float num1, float num2) {
      System.out.println(num1 - num2);
  }
      public static void product(float num1, float num2) {
      System.out.println(num1 * num2);
  }
   public static void main (String[] args)
   {
      float num1, num2;
  Scanner scan = new Scanner (System.in);

      System.out.print ("Enter the first number: ");
      num1 = scan.nextFloat();
      System.out.print ("Enter the second number: ");
      num2 = scan.nextFloat();
    sum(num1, num2);
    difference(num1, num2);
    product(num1, num2);
   }
}

3. 계산기(

import java.util.Scanner;
 
class Mycalculator { 
    public Mycalculator(float num1, float num2) {
        
    }
        float num1, num2;
     public void sum(float num1, float num2) {
      System.out.println(num1 + num2);
  }
    public void difference(float num1, float num2) {
      System.out.println(num1 - num2);
  }
      public void product(float num1, float num2) {
      System.out.println(num1 * num2);   
    }
    
}
public class FloatCalculations2 {   

 public static void main(String[] args) {
float num1 = 0, num2 = 0;
     Mycalculator cal = new Mycalculator(num1, num2);
Scanner scan = new Scanner (System.in);
      System.out.print ("Enter the first number: ");
      num1 = scan.nextFloat();
      System.out.print ("Enter the second number: ");
      num2 = scan.nextFloat();
   cal.sum(num1, num2);
   cal.difference(num1, num2);   
   cal.product(num1, num2);
 }
      
            
}