Article: You can find it around your keyboard's numpad, or as a secondary function on another key. The Num Lock key is primarily used to lock the number keys on your numpad, but you can also use it to disable your Fn key. This will allow you to use the Num Lock button, and disable Fn. This will instantly disable all of your Fn key's functions. The Num Lock key may also look like Num ⇩ on some keyboards.

What is a summary?
Find the Num Lock key on your keyboard. Hold down the Fn key on your keyboard. Press the NumLock key while holding down Fn.