device.rb

#!/usr/bin/env ruby
class Device
  attr_accessor :name
  attr_reader :calculations

  def initialize    
    @calculations = []
  end
  
  def build_calculation(name)
    calculation = Calculation.new
    calculation.name = name
    @calculations << calculation
    extend Object.const_get("Methods").const_get(name)
  end
end

class Calculation
  attr_accessor :name  
end

module Methods
  module NickMath
    def sum(a,b)
      a + b
    end
  end
end

module Methods
  module Jon
    def program
      puts "Jon is beginning to program"
    end
  end
end

device = Device.new
device.name = "My Device"

device.build_calculation("NickMath")
s = device.sum(1,2)
puts "The sum of the numbers is #{s}"

device.build_calculation("Jon")
device.program