# File lib/sass/script/value/number.rb, line 366
    def coerce(num_units, den_units)
      Number.new(if unitless?
                   value
                 else
                   value * coercion_factor(@numerator_units, num_units) /
                     coercion_factor(@denominator_units, den_units)
                 end, num_units, den_units)
    end