with the partials and rendering, this is what i was referring to about using locals instead to make partials easier to understand/reuse.

Swap this render call for something along the lines of...

```ruby
<%= render(
  :partial => 'checkout_summary', 
   :locals => { :addresses => @checkout.addresses, :cart => @checkout.cart }
)
%>
```

Then in your view, you reference the locals as you would any other local variable...

```<% addresses.each do |address| %>```

This ensures that the partials are easier to re-use and easy to manage the code around them