By default, the numpad is not activated when you arrive to login window. To activate it, you need to install a package. Shown with Linux Mint Cinnamon.
- Open a Terminal.
- Type
sudo apt install numlockxto install the package. - Once installed, just confirm in the Terminal with:
sudo numlockx on - (Linux Mint) – Open the Login Window manager with:
sudo lightdm-settings - In Settings tab, verify that Activate numlock is checked.
Now, numpad will always be on each time you start your computer.
FrenchSavvy 