Assignment #103 and Keychains for Sale, real ultimate power

Code

    /// Name: Brendan Baird
    /// Period: 6
    /// Program Name: Keychains for Sale, real ultimate power
    /// File Name: KeychainsUltimate.java
    /// Date Finished: 1/15/2016
    
    import java.util.Scanner;

    public class KeychainsUltimate
    {
        public static void main(String[] args)
        {
            Scanner k = new Scanner(System.in);
            int choice;
            int numberOfKeys = 0;
            int pricePerKey = 10;
            double tax = .0825;
            int baseShipping = 5;
            int perKeychainShipping = 1;
    
            System.out.println("Ye Olde Keychain Shoppppe");
    
            do
            {
                System.out.println();
                System.out.println("1. Add Keychains to Order");
                System.out.println("2. Remove Keychains from Order");
                System.out.println("3. View Current Order");
                System.out.println("4. Checkout");
                System.out.println();
                System.out.print("Please enter your choice: ");
                choice = k.nextInt();
    
                System.out.println();
    
                if (choice == 1)
                {
                    numberOfKeys = addKeychains( numberOfKeys );
                    System.out.println("You now have " + numberOfKeys + " keychains.");
                }
                else if (choice == 2)
                {
                    numberOfKeys = removeKeychains( numberOfKeys );
                    System.out.println("You now have " + numberOfKeys + " keychains.");
                }
                else if (choice == 3)
                    viewOrder( numberOfKeys, pricePerKey, tax, baseShipping, perKeychainShipping );
                else if (choice == 4)
                    checkout( numberOfKeys, pricePerKey, tax, baseShipping, perKeychainShipping );
                else
                    System.out.println("ERROR");
            } while (choice != 4);
        }
    
        public static int addKeychains(int numberOfKeys)
        {
            Scanner k = new Scanner(System.in);
            int keyNumberNow;
            int add;
    
            do
            {
                System.out.print("You have " + numberOfKeys + " keychains. How many to add? ");
                add = k.nextInt();
                
                if ( add < 0 )
                    System.out.println("Sorry, but you cannot ask for a negative number of keychains.");
            } while ( add < 0 );
            
            keyNumberNow = numberOfKeys + add;
            
            return keyNumberNow;
        }
    
        public static int removeKeychains(int numberOfKeys)
        {
            Scanner k = new Scanner(System.in);
            int keyNumberNow;
            int remove;
    
            do
            {
                System.out.print("You have " + numberOfKeys + " keychains. How many to remove? ");
                remove = k.nextInt();
    
                if ( numberOfKeys < remove )
                    System.out.println("Sorry, but you cannot remove that many keychains.");
                if ( remove < 0 )
                    System.out.println("You cannot remove a negative number of keychains.");
            } while ( numberOfKeys < remove || remove < 0 );
            
            keyNumberNow = numberOfKeys - remove;
    
            return keyNumberNow;
        }
    
        public static void viewOrder( int numberOfKeys, int pricePerKey, double tax, int baseShipping, int perKeychainShipping )
        {
            double totalCost;
    
            System.out.println("You have " + numberOfKeys + " keychains.");
            System.out.println("Keychains cost $" + pricePerKey + " each.");
            System.out.println("Shipping charge is $" + baseShipping + " plus $" + perKeychainShipping + " per keychain.");
            
            totalCost = (numberOfKeys * pricePerKey) + (numberOfKeys * perKeychainShipping) + baseShipping;
            
            System.out.println("Your subtotal before tax is $" + totalCost + ".");
            System.out.println("The tax on your order is " + (tax * 100) + "%.");
            
            totalCost = (totalCost * tax) + totalCost;
    
            System.out.println("Your final cost is $" + totalCost + ".");
        }
    
        public static void checkout( int numberOfKeys, int pricePerKey, double tax, int baseShipping, int perKeychainShipping )
        {
            Scanner k = new Scanner(System.in);
    
            System.out.println("CHECKOUT");
            System.out.println();
    
            System.out.print("What is your name? ");
            String name = k.next();
    
            viewOrder( numberOfKeys, pricePerKey, tax, baseShipping, perKeychainShipping );
            
            System.out.println("Thanks for your order, " + name + "!");
        }
    
    }
    

Picture of the output