If you’ve tried Linux before, chances are you found this frustrating. The NumLock key on your keyboard is by default OFF when Linux boots. There’s a way to enable NumLock key stay in the ON state when Linux starts up.
Here’s how to do it if you’re in Ubuntu:
Using the shell, install NumLockX by typing this command
$ sudo apt-get install numlockx
Otherwise you can download the tarball from here, compile and install it by executing the following set of commands from the directory where the tarball was extracted:
./configure
make
make install
make xsetup
make xinitrc
Reboot, you should see that the NumLock key is on by default.