title: Ruby object prints out as pointer
body: <p>I'm trying to create a class, which has a constructor that takes a single argument. When I create a new instance of the object, it returns a pointer.</p>
  
  <pre><code>class Adder
      def initialize(my_num)
          @my_num = my_num
      end
  end
  y = Adder.new(12)
  puts y
  </code></pre>
  
  <p>What am I doing wrong?
  Thanks</p>