I figured out that to use the NumLock you have to turn it on, And then press and hold the Function (Fn) key in order to use the number pad on the keyboard.
I have an old Dell Latitude D630. This is the default setting. Another completely unintuitive default setting.
This is controlled by BIOS settings. Reboot and press F2 to get into the settings.
Find and change these two settings. One to use Numlock only. And another to turn Numlock off when booting.
I finally figured out how to use the NumLock key on my laptop