Google Docs for tablets (Docs, Sheets, and Slides) currently (2016-17) offer only a small subset of the features found on their full versions on the Google Drive site.
If you need access to the more advanced features you will need to access Google drive via the full desktop version of Google Drives web site.
Please follow the instructions listed for your device.
To access the full features of Google Docs on any Android device
Once this page loads you have the ability to create new docs, sheets, or slides
The new tab will have reverted to the mobile web site
You should now have the full version of the app you want.
To access the full features of Google Docs on any iOS device
Once this page loads you have the ability to create new docs, sheets, or slides
The new tab will have reverted to the mobile web site
You should now have the full version of the app you want.