gistfile1.rb

# divide an array with one pint too many
class Array
  def /(divider)
    divider = divider.to_i
    collection_size = size / divider
    array = []
    each_with_index do |element, index|
      index % collection_size == 0 && divider != array.size ? array << [element] : array.last.push(element)
    end
    array.size == 1 ? array.flatten! : array
  end
end

# ruby-1.8.7-p299 > (1..25).to_a / 5
# => [[1, 2, 3, 4, 5], [6, 7, 8, 9, 10], [11, 12, 13, 14, 15], [16, 17, 18, 19, 20], [21, 22, 23, 24, 25]]