# File lib/sass/script/number.rb, line 294
    def coerce(num_units, den_units)
      Number.new(if unitless?
                   self.value
                 else
                   self.value * coercion_factor(self.numerator_units, num_units) /
                     coercion_factor(self.denominator_units, den_units)
                 end, num_units, den_units)
    end