How do I stop App Store multiple downloads I upgraded to Mavericks a couple of days ago.
Yesterday I "upgraded" Numbers and Pages (incidentally don't do this - they have LESS functionality).

Now App Store is trying to download Numbers and Pages again. I have already downloaded Numbers at least twice, now it is trying again!

How do I stop this?

I may have caused this by clicking "Update" more than once or selecting "Check for unfinished downloads".
Unfortunately App Store no longer gives any indication when you click "Update"
Check to see if you still have the "iWork '09" folder in your main Applications folder.  The updated versions don't replace the old ones there, so the App Store keeps seeing the previous version and thinks you need to update.  (iMovie and GarageBand have the same issue; previous versions were installed into a folder inside the Applications folder.)