What is Num Lock?

Michael Pollick
Michael Pollick

Just to be clear, num lock is not the least popular item on a Chinese menu, nor is it a security measure for wayward nums. Actually, it is a key found on most computer keyboards near the 10-key numeric pad. The term is short for numeric lock or number lock, the function of which is now considered largely ornamental and historical. There is also a corresponding light which indicates when the key has been activated or deactivated.

Compact keyboards, such as those on many laptops, often lack a 10-key numeric pad and therefore do not have a num lock key.
Compact keyboards, such as those on many laptops, often lack a 10-key numeric pad and therefore do not have a num lock key.

When IBM first introduced personal computers, the original keyboards combined the standard 10-key numeric pads with a second set of cursor controls. The num lock key acted as a toggle switch between the two sets of commands. When the key was switched on, the numeric keypad would work exclusively as a form of calculator. Switching it off would convert the keys to cursor controls, allowing users to manipulate the cursor in four directions or send it to the top or bottom of the page.

More modern computer keyboards use separate keys for cursor control, reducing the need for a num lock key. The numerical keypad on almost all modern keyboards is set to lock by default. Occasionally, a computer will remember the setting during shut-down and restore that setting during restart. This means if the user turns off the num lock for gaming or programming purposes, it will remain off during the restart process.

The key has not become completely obsolete — there are still a few programming functions which benefit from its presence. Some computer gamers find that the numeric keypad is easier to manipulate than the separate direction and cursor control keys of modern keyboards. Web surfers may also find the unlocked numeric keypad to be useful while scrolling through large websites. The next generation of keyboard design may eliminate the num lock key altogether, but there was a time when it served a definite purpose for early computer users.

Michael Pollick
Michael Pollick

A regular EasyTechJunkie contributor, Michael enjoys doing research in order to satisfy his wide-ranging curiosity about a variety of arcane topics. Before becoming a professional writer, Michael worked as an English tutor, poet, voice-over artist, and DJ.

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Discussion Comments


There are few things that annoy me more than the Num Lock. When using the 10-key and the Qwerty number pads interchangeably, it is infuriating to find the lock, especially after typing several keys in the 10-key and messing up the number fields I just tabbed through. The Num Lock should be eliminated, immediately.


So...what's the difference between the num lock and the scroll lock? It sounds to me like they do the same thing.

Also, why do keyboards still have Caps Lock? I as taught in second grade not to use caps lock, as it was the incorrect way to insert capital letters. If that's true, then why haven't we gotten rid of it? Especially now, when (what I assume are) "hunt & peck" types forget to "turn off" the caps lock (and thus make the rest of us more savvy typists assume the person is an idiot. I figure they aren't. Just not tech savvy, and on the 'net, that makes you seem like an idiot to those of us who use our computer daily).

Also: What's the politest way for me to tell my friends who are new to email *not* to send out forwards? My preferred method is usually just send it right back, but there are some people I actually *like* and I don't want to hurt their feelings (or spam them back, as the case may be).

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