I am a new Mac user, having worked on PC's for 30 years. I have an iPhone 3GS 16GB, iPad with Wifi 32GB and a new MacBook Pro. I have a question about moving and changing files. I have created a Numbers file on the MacBook and using Dropbox I have enabled the viewing of the file in Dropbox on the iPhone and iPad. Can I remove the file from Dropbox and put it into Numbers on the iPad, make a change to the file on the iPad, put back into Dropbox and send it to the MacBook to update the original file? If so, how do I get it out of Dropbox and into Numbers and then back into Dropbox to send back to the MacBook. If not, is there an avenue to do a change to the file?