num.rb

class Bignum
  def ==(o)
    puts "=="
    super
  end
  
  def eql?(o)
    puts "eql?"
    super
  end
end

10_000_000_000_000_000.eql? 1
1.eql? 10_000_000_000_000_000


class MyNumber < Numeric
  def ==(o)
    puts "=="
    super
  end

  def eql?(o)
    puts "eql?"
    super
  end
end

m = MyNumber.new

10.eql? m
m.eql? 10