turning a repeating decimal into fraction

repeating_decimal.rb

class Numeric
  def £(other_number)
    RepeatingDecimal.new(self, other_number)
  end
end

class RepeatingDecimal
  attr_reader :repeating

  def initialize(base, repeating)
    @base = base
    @repeating = repeating

    @base_number = 0
    if @base.is_a? Float
      @base_number = "#{@base}#{@repeating}".to_f
    else
      @base_number = "#{@base}.#{@repeating}".to_f
    end
  end

  def *(number)
    base_calculation = @base_number

    if decimal_count == 1
      base_calculation = "#{@base_number}#{@repeating}".to_f
    end
    number = base_calculation * number

    RepeatingDecimal.new(number, @repeating)
  end

  def -(number)
    raise "Subtracts only for another RepeatingDecimal" unless number.is_a? RepeatingDecimal

    raise "Unable to subtract from another base" if self.repeating != number.repeating

    @base.to_i
  end

  def as_fraction
    calculated_number = self * multiplier
    calculated_number -= self

    "#{calculated_number}/#{(multiplier-1)}"
  end

  def to_s
    @base_number.to_s + "..."
  end

  protected

  def multiplier
    @multiplier ||= ("1" + ("0" * @repeating.to_s.size)).to_i
  end

  def decimal_count
    @base_number.to_s.split('.').last.size.to_i
  end
end

puts "Fraction of 0.44... = " + 0.£(4).as_fraction
puts "Fraction of 1.23999... = " + 1.23.£(9).as_fraction
puts "Fraction of 0.12398769876... = " + 0.123.£(9876).as_fraction