Exercise: Methods and BigDecimal

In this exercise, you will practice working with methods and BigDecimal numbers.

Write a console program that:

Has a method bigAdd that adds two ints and produces a BigDecimal.
Has a method digitSum that calculates the digit sum of a given BigDecimal, returning an int.
Has a method digitsToWords that converts an int to a string consisting of the English words of its digits.

Here's how the body of your main method should look:

System.out.print("Adding 5 to Integer.MAX_VALUE: ");
BigDecimal result = bigAdd(5, Integer.MAX_VALUE);
System.out.println(result);
System.out.print("Digit sum of " + result + ": ");
int digitSum = digitSum(result);
System.out.println(digitSum);
System.out.print("Digits as words: ");
String words = digitsToWords(digitSum);
System.out.println(words);

Program output:

Adding 5 to Integer.MAX_VALUE: 2147483652
Digit sum of 2147483652: 42
Digits as words: four two

Hints 💡

You can use equals to check whether two BigDecimal numbers are equal.
Use the remainder method instead of % to extract the last digit of a BigDecimal.
To do integer division with BigDecimal, use number.divide(BigDecimal.TEN, RoundingMode.FLOOR).

Hand in instructions

Make sure your program runs correctly.
Hand in your program by uploading Main.java to Moodle.