Adding resources to a Bulletin Board

I'd like to know if I can use the 'open in' function to add a resource to a bulletin board as opposed to using the add function within the bulletin board itself which requires me to have saved the doc to Dropbox previously. I have tried open in and can navigate to the bulletin board but the doc doesn't appear.

Yes, you can use the 'Open in' feature but if the targeted bulletin board is open at that very same moment it won't update its contents. As soon as you go back to it you will see the files.

Ah, I see now. Thanks so much Bert.

Another quick question if you don't mind. I can see how to calculate an average across columns but not how to do it within (down) a column to get the class average on an assignment.

Here it is. Tap on the first empty row