I have a Microsoft Keyboard and i don’t know what happened all of a sudden numeric keypad wasn’t working so i though there was some issue in my keyboard so i changed the keyboard but i was surprised to see problem was same again this time.
So i searched on Google and found that there was some Keyboard settings in Windows and Ubuntu.
In Ubuntu here it is how can we change it
3) Keyboard (Tab: Mouse Keys)
4) Uncheck (Allow to control pointer using the keyboard).