If you prefer that the NumLock is activated automatically when you turn on your computer, then follow the instructions in this post.
Install the package numlockx :
– For ubuntu and other debian based
sudo apt-get install numlockx
– Fedora and other rpm based
yum install numlockx
– Now edit /etc/gdm/Init/Default  and inert the bellow code.
sudo vi /etc/gdm/Init/Default
and insert this lines:
if [ -x '/usr/bin/numlockx' ]; then /usr/bin/numlockx on fi save , exit
Is done.
