I wanted to have the Numlock ON at login time to facilitate typing in my password. I searched the forums but didn't find a solution. So here is a solution that works for me. I am running LXLE-1404 64bit on an AMD desktop system.

First, make sure you have the numlockx package installed. ;)

Open a terminal and edit the file: /etc/lightdm/lightdm.conf.d/20-lubuntu.conf

Add this line to the bottom of the file: