Enable Number pad NumLock at startup in Ubuntu Login Window

Install numlockx by this command in terminal(Applications/Accessories/Terminal):

sudo apt-get install numlockx

edit /etc/gdm/Init/Default with your favourite editor:

sudo gedit /etc/gdm/Init/Default

add following above the last line which says exit 0:

if [ -x /usr/bin/numlockx ]; then
/usr/bin/numlockx on
fi