How to get word count for multiple text docs?

I want to get the collective word count from several text docs within a folder.

What is the quickest, easiest way to get this?

When I highlight several I do not see the collective word count appear anywhere.

Probably the simplest way to get a quick estimate is to hold down Command and click on the documents you want to count up. This will create a “Multiple Selection” in the main editor. Switch that over to Scrivenings mode with ⌘1, and the cumulative word count will be displayed along the bottom of the editor. Click on the counter in the footer bar to get more stats.

For larger groups of documents, the Project ▸ Statistics… panel is probably best. The second tab will show the stats for the current selection, which by default will also count up all subdocuments as well.