Low on memory on your phone? Can't install FACEBOOK app? Don't worry! I have been using FACEBOOK, on my low memory phone flawlessly. Open Chrome browser. Go to facebook.com and log in. It might ask to send notifications. Allow it. That's the quickest way. But if it doesn't ask, then try this: open burger menu( three vertical lines )
Then go back to settings
Thats it! You are ready!