Keyboard number pad not working

I am running Ubuntu 9, and recently I have a very strange error.

My number pad on my keyboard don't work. Its not hardware since I changed the keyboard and I still have the same problem.

It could be your mouse settings. Your keyboard is set to move the cursor with your number pad.

To Slove this issue

1. Go to System > Preferences > Accessibility > Keyboard Accessibility
2. Select [x] Enable keyboard accessibility features
3. Go to the tab Mouse Keys and deselect [ ] Enable keyboard accessibility features.

similar to article: http://arcanecode.com/2007/04/25/ubuntu-704-and-virtual-pc-2007-mouse-issue-workaround-sort-of/

On a Mint 18.2 encountered a similar problem
Menu > Accessibility > Mouse > switch off Control the pointer using the keypad
screen guide: switch on numpad linux mint