Google Drive Offline
USING GOOGLE DRIVE WITHOUT INTERNET ACCESS
You can use your Chromebook to work on files in your Drive, like word processing documents and presentations, even if you don't have wi-fi access. The first thing you need to do, while you are still somewhere with internet access, is to go into the settings in Drive and make sure offline sync is enabled. Check out the video below if you aren't sure how to do that.
Be sure to remember that if you follow the steps in the video to ensure Drive is set to allow offline work, you will still need to open documents your teacher assigns in a location where you do have wi-fi access first. Opening it will save the document to the hard drive on your Chromebook, and you can then work on it later in a location without wi-fi.