I personally like the num lock key to be switched on by default once I've logged in to KDE. For me, it's much more useful to have access to the numeric keypad as, just that, a numeric keypad, than it is to have a glorified arrow key navigation pad.
If, like me, you want to have NumLock on as soon as KDE starts, the option is a pretty simple one to tweak. The option is a bit buried, however, and if you don't know where you're looking this issue can get annoying.
Open the KDE Control Centre by pressing Alt-F2 and launching kcontrol. Once the Control Centre is open, browse to Peripherals > Keyboard
Once you're there, choose the Turn On option and Apply your changes. Simple!
Kubuntu (and some other KDE-based distributions) features a special System Settings application which takes the place of the full KDE Control Centre application, which is used for setting all sorts of KDE preferences and changing different settings on the system.
However, many people like the older KDE Control Centre layout, especially if you're a longer time KDE user or can't find the option you're looking for in the System Settings applet. Unfortunately, it's nowhere to be seen on the menu.
To launch the original KDE Control Centre, go to your desktop and press Alt-F2. Now type kcontrol and press Enter. You should get the original, unadulterated KDE Control Centre.
If you want to now make KControl available on the menu, you will have to add it manually using the Menu Editor. Press Alt-F2 again, but this time enter the command kmenuedit to bring up the menu editor.
Right-click a suitable category, I'll pick Utilities, and click New Item.
Name it whatever you find suitable, and under the Command box, type kcontrol. You can also click the generic file icon in the top right to set a custom icon for the new entry. Once you're done, hit Save and next time you'll be able to access the 'real' KControl when you need it, or all the time if you prefer, with a lot more ease.
