Check working with ruby 1.9.3.

[kslazarev]

ruby-1.9.3-p0-fast :001 > require 'numbers_and_words'
=> true
ruby-1.9.3-p0-fast :002 > 177.to_words
NoMethodError: undefined method `capacity_count' for [7, 7, 1]:Array

[kslazarev]

Now, It's work on ruby 1.9.3.