Convert numbers to Bulgarian words - list of numbers is incomplete (and It's not intended to be complete)

document_helper.rb

# Example
# in template: <%= number_to_bg_words something.price, :format => '%i и %f' %>
# result: триста и дванадесет лева и петдесет и шест стотинки
########################
# encoding: UTF-8
module DocumentHelper

  @@number_to_word = {
    '1' => 'един',
    '2' => 'два',
    '3' => 'три',
    '4' => 'четири',
    '5' => 'пет',
    '6' => 'шест',
    '7' => 'седем',
    '8' => 'осем',
    '9' => 'девет',

    '10' => 'десет',
    '11' => 'единадесет',
    '12' => 'дванадесет',
    '13' => 'тринадесет',
    '14' => 'четиринадесет',
    '15' => 'петнадесет',
    '16' => 'шестнадесет',
    '17' => 'седемнадесет',
    '18' => 'осемнадесет',
    '19' => 'деветнадесет',

    '20' => 'двадесет',
    '30' => 'тридесет',
    '40' => 'четиридесет',
    '50' => 'петдесет',
    '60' => 'шейсет',
    '70' => 'седемдесет',
    '80' => 'осемдесет',
    '90' => 'деветдесет',

    '100' => 'сто',
    '200' => 'двеста',
    '300' => 'триста',
    '400' => 'четиристотин',
    '500' => 'петстотин',
    '600' => 'шестстотин',
    '700' => 'седемстотин',
    '800' => 'осемстотин',
    '900' => 'деветстотин',

    '1000' => 'хиляда',
    '2000' => 'две хиляди',
    '3000' => 'три хиляди',
  }

  def number_to_bg_words(number)

    integer_words = []
    fractional_words = []
    num_s = number.to_s

    if number.kind_of? Float

      int = num_s.gsub /\.\d+/, ''
      fra = num_s.gsub /^\d+\./, ''

      # before decimal point
      find_word(int, integer_words)

      # after
      if fra.to_i > 0
        find_word(fra, fractional_words)
      end

    elsif number.kind_of? Fixnum

      find_word(num_s, integer_words)    
    else
      return
    end

    output = String::new

    unless integer_words.empty?
      output << "#{integer_words.join(' и ')} лева"
    end

    unless fractional_words.empty?
      output << " и #{fractional_words.join(' и ')} стотинки"
    end

    output.html_safe
  end

  private

  def find_word (num_str, words_list)
    num_length = num_str.length

    num_length.times do |i|

      if @@number_to_word[num_str[i,num_length]].nil? == false

        words_list.push @@number_to_word[num_str[i,num_length]]

        break
      else

        round = num_str[i]

        (num_length - (i + 1)).times { round << 0.to_s }

        if @@number_to_word[round].nil? == false
          words_list.push @@number_to_word[round]
        end
      end
    end
  end

end