class SassC::Script::Value::Number

def normalize!
  return if unitless?
  @numerator_units, @denominator_units =
    sans_common_units(@numerator_units, @denominator_units)
  @denominator_units.each_with_index do |d, i|
    next unless convertable?(d) && (u = @numerator_units.find {|n| convertable?([n, d])})
    @value /= conversion_factor(d, u)
    @denominator_units.delete_at(i)
    @numerator_units.delete_at(@numerator_units.index(u))
  end
end