For desktops and laptops that have a separate numeric keypad, it might be useful for NumLock to be turned on automatically when your Ubuntu boots up. This quick tutorial will show you how to do it in Ubuntu 14.04.
First click the below button to bring up Ubuntu Software Center and install numlockx.
Then press Alt+F2 and paste below command into the dash.
gksudo gedit /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
Hit enter and type your password when prompt. It will open the lightdm config file with gedit text editor.
Next to do is add below line into the end and save the file:
Finally restart your computer. The numeric keypad should turn on automatically when you’re at the login screen, and stay on after logging in.
Tip: In my case, NumLock was turned off again during login. If this happens to you, add numlockx as a startup program:
command: sleep 20 && numlockx on