I need help debugging this program

/** * @author Jeffrey Light */ package week11; import java.util.ArrayList; // Needed to use ArrayLists import java.util.Scanner; // Needed for user input public class Debugger { /** * Main method to launch a Math Games application. * The application will allow users to select from a menu of choices such as Find the Sum, Find the Average and Find the Biggest. * Presents a menu to the user and calls the playMath() method with the associated argument. * * @param args Command line input. Not intended for use. * @return void */ public static void main(String[] args) { Scanner sIn = new Scanner(System.in); //Input Scanner for String String choice; boolean done = false; do { //Describe the program functionality System.out.println("This program will give the user the opportunity to try several different math games."); System.out.println("Select a math game from the menu to play. "); //Present the user with a menu of choices System.out.println("1: Find the Sum"); System.out.println("2: Find the Average"); System.out.println("3: Find the Biggest"); System.out.println("4: Exit"); System.out.print("Please enter a command: "); choice = sIn.nextLine(); //Call the playMath method passing the appropriate argument switch (choice) { case "1": playMath(sIn, "sum"); break; case "2": playMath(sIn, "average"); break; case "3": playMath(sIn, "biggest"); break; case "4": System.out.println(" Goodbye!"); done = true; default: System.out.println(" Invalid response! Please enter a number between 1-4. "); }//end of switch (choice) }while (!done); //end of do/while(!done) }//end of main() /** * Returns void. * Allows the user to enter in a series of numbers (whole or double) and loads them into an ArrayList called numList. * Calls the appropriate method to compute the results * Displays the final results to the console. * * @param sIn Scanner object to get input from the user * @param game A String indicating the game the user chose to play. Will = "sum", "average", or "biggest". * @return void */ public static void playMath(Scanner sIn, String game) { String input = ""; //String variable to hold the user input double num = 0; //Double variable to hold the user input after converted to a number double result = 0; //The value returned from the method called. ArrayList numList = new ArrayList(); //ArrayList of Doubles to hold the numbers entered by the user System.out.printf(" You will enter a series of numbers (either whole or decimal) and we will find the %s. ",game); //Keep adding numbers until the user hits enter without any data. while (true) { System.out.print("Please enter a number (or just hit enter to finish): "); input = sIn.nextLine(); if (input.equals("")) { break; //If the user just hits enter, leave the program. }else { try { num = Double.parseDouble(input); //Input validation. Try to convert the user's input into a double. numList.add(num); //If successfully converted, add the user's input to the ArrayList }catch(Exception e) { System.out.println("Invalid response. Please enter a valid number. "); }//end of try/catch }//end of if (input.equals("")) }//end of while(true) //Keep adding numbers ... if(game.contentEquals("sum")) { result = sumNumbers(numList); //Call the sumNumbers() method }else if(game.contentEquals("average")) { result = avgNumbers(numList); //Call the avgNumbers() method }else { biggestNumber(numList); //Call the biggestNumber() method }//end of if/else if/else (game.contentEquals("sum") //Print out the result System.out.println("-----------------------"); System.out.printf("The %s is: %,.2f ",game, result); }//end of method playMath(Scanner, String) /** * Returns double. * Add us all the numbers in an ArrayList and returns the total. * Displays each number in the ArrayList and the Running Total. * * @param numList The ArrayList of numbers entered by the user. * @return result */ public static double sumNumbers(ArrayList numList) { double result = 0; //Initialize the result System.out.printf("%-12s%s ","Number", "Running Total"); //Print the header for (int i = 0; i < numList.size()-1; i++) { //Process every number in the ArrayList result = result + numList.get(i); System.out.printf("%,-15.2f%,.2f ",numList.get(i), result); //Print the running total }//end of for (int i = 0; i < numList.size(); i++) return result; //Return the result }//end of method sumNumbers(ArrayList) /** * Returns double. * Add us all the numbers in an ArrayList and returns the average. * Displays each number in the ArrayList and the Running Average. * * @param numList The ArrayList of numbers entered by the user. * @return result */ public static double avgNumbers(ArrayList numList) { double result = 0; //Initialize the result double sum = 0; //Initialize the running sum System.out.printf("%-12s%s ","Number", "Running Average"); //Print the header for (int i = 0; i < numList.size(); i++) { //Process every number in the ArrayList sum = sum + numList.get(i); System.out.printf("%,-15.2d%,.2d ",numList.get(i), (sum/(i+1))); //Print the running average }//end of for (int i = 0; i < numList.size(); i++) result = sum / numList.size(); //Calculate the average return result; //Return the result }//end of method avgNumbers(ArrayList) /** * Returns double. * Evaluates all the numbers in an ArrayList and returns the biggest. * Displays each number in the ArrayList and the Running Biggest. * * @param numList The ArrayList of numbers entered by the user. * @return result */ //Method biggestNumber() which returns the biggest number in an array public static double biggestNumber(ArrayList numList) { double result = 0; //Initialize the result System.out.printf("%-12s%s ","Number", "Running Biggest"); //Print the header for (int i = 0; i < numList.size(); i++) { //Process every number in the ArrayList if(numList.get(i) > result) { result = numList.get(i); //If the number processed is bigger than the current biggest, it is the new biggest }//end of if(numList.get(i) > result) System.out.printf("%,-15.2f%,.2f ",numList.get(i), result); //Print the running average }//end of for (int i = 0; i < numList.size(); i++) return result; //Return the result }//end of method biggestNumber(ArrayList) }//end of class Lab 11a