english_number created by jmkoni - https://repl.it/@jmkoni/englishnumber

english_number.rb

class NumberPrinter
  ONES = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
  TEENS = ["ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
  TENS = ["ten", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
  TRANSLATION = { hundred: 100, thousand: 1000, million: 1000000, billion: 1000000000}

  attr_accessor :number

  def initialize(number)
    @number = number
  end

  def print_english_number
    print_number(@number)
  end

  private
  def print_number(number)
    full_number = ""
    full_number += "negative " if number < 0
    number = number.abs
    if number < 10
      full_number += get_ones(number)
    elsif number < 20
      full_number += get_teens(number)
    elsif number < 100
      full_number += get_tens(number)
    else
      full_number += get_greater(number)
    end

    full_number
  end

  def get_ones(number)
    ONES[number]
  end

  def get_teens(number)
    TEENS[number - 10]
  end

  def get_tens(number)
    tens = number / 10
    remainder = get_remainder(number, 10)
    TENS[tens - 1] + " " + remainder
  end

  def get_greater(number)
    TRANSLATION.each do |size, divisor|
      if right_divisor?(number, divisor)
        text = print_number(number / divisor)
        remainder = get_remainder(number, divisor)
        return text + " " + size.to_s + " " + remainder
      end
    end
  end

  def right_divisor?(number, divisor)
    less_thousands?(number, divisor) or thousands_or_more?(number, divisor)
  end

  def less_thousands?(number, divisor)
    divisor < 1000 and (1..9).include?(number / divisor)
  end
  
  def thousands_or_more?(number, divisor)
    divisor >= 1000 and (1...1000).include?(number / divisor)
  end

  def get_remainder(number, divisor)
    mod = number % divisor
    remainder = mod > 0 ? print_number(mod) : 0
  end
end

num = NumberPrinter.new(1927838982)
puts num.print_english_number