This quick guide will show you how to make the Num Lock on always when you loggin KDE.
You should start the System Settings located in K menu -> System Settings.
Once you open the System Settings you should go to Peripherals -> Keyboard from the menu tree in left as it’s shown on the picture below.
Once you are in Peripherals -> Keyboard you should see NumLock on KDE Startup area. There you should see Turn On option and you should click on the radio button in front of it as it’s shown on the picture above. Once this is done you can click on the Apply button and the next time you boot your OS and load KDE your Num Lock will be ON. Have fun 🙂