module Basic
	def add(number)
		self + number
	end
end

Fixnum.class_eval do
	include Basic
end

3.add 4  #=> 7

module ExtendMe
	def verbal_object_id
		 "my object id is #{self.object_id}"
	end
end

class Person
	extend ExtendMe
end

Person.verbal_object_id #=> "my object id is 24339630"

module ExtendThroughInclude
	def self.included(klass)
		klass.extend ClassMethods
	end

	def instance_method
		"this is an instance method of #{self.class}"
	end

	module ClassMethods
		def class_method
			"this is a method on the #{self} class"
		end
	end
end

class Person
	include ExtendThroughInclude
end

Person.new.instance_method #=> "this is an instance method Person"
Person.class_method #=> "this is a method on the Person class"