Recently the numpad stopped working for some reason. I didn’t bother going into it because I didn’t use that much. The num lock was on but there was nothing to suggest the keyboard was broken.
Ubuntu Forum to the rescue. A quick search later reveled a post that you can control the mouse cursor using your numpad. Changing the settings in
System > Preferences > Assistive Technologies select Keyboard Accessibility and Mouse Key tab to deselect the tick box “Allow to control the pointer using the keyboard” and my numpad was back to normal.