After 3 days of head-banging, I thought I would share this info to save you the excruciating headache.
These are the steps for getting the sum of a field from your node. You're going to need VBO(Views Bulk Operations), Views, and Rules.
Create a new view of Content and select your content type. No need to create a page or a tab(unless you really want to).
Add the views fields and filters that you want.
Create a Content:Views Bulk Operation(leave the defaults in).