PLEASEI NEED CHANGE TO DECIMAL FORMULA ......HOW CAN TO CHANGE DECIMAL .....!!!!!!

public double calculateTotalBill() { return calculateSubTotal() + calculateSales Tax(); * @param * @return void */ public void printReceipt) { System.out.println("**********RECEIPT**********"); System.out.println("Customer Input"); System.out.println("Basket Type : "+basketType); System.out.println("Customer Type : "+customer Type); System.out.println("Accessory Type : "+accessory Type); System.out.println("State :"+state); System.out.println("***************************"); System.out.println("Basket Amount "+basketAmount()+" ,Discount "+calculateDiscount()); System.out.println("sales tax "+calculateSales Tax()); System.out.println("Your total bill payable "+calculateTotalBill()); System.out.println("***********Thanks***********"); public double calculateTotalBill() { return calculateSubTotal() + calculateSales Tax(); * @param * @return void */ public void printReceipt) { System.out.println("**********RECEIPT**********"); System.out.println("Customer Input"); System.out.println("Basket Type : "+basketType); System.out.println("Customer Type : "+customer Type); System.out.println("Accessory Type : "+accessory Type); System.out.println("State :"+state); System.out.println("***************************"); System.out.println("Basket Amount "+basketAmount()+" ,Discount "+calculateDiscount()); System.out.println("sales tax "+calculateSales Tax()); System.out.println("Your total bill payable "+calculateTotalBill()); System.out.println("***********Thanks***********")