The Goobric extension is an easy way to grade assignments that are stored in Google Drive. Just install the extension, log in to your Google Account, and get started! You can mark any folder or Google Sheet as eligible for grading. 

The score you get for each assignment will be calculated based on the criteria you set for it. To access the criteria, click on the "Description" button. There you can see which marks are eligible for that particular assignment. This also includes navigation buttons so you can move through various assignments without having to switch tabs.