Num Lock Explained

Num Lock or Number Lock () is a key on the numeric keypad of most computer keyboards. It is a lock key, like Caps Lock and Scroll Lock. Its state affects the function of the numeric keypad commonly located to the right of the main keyboard and is commonly displayed by an LED built into the keyboard.

The Num Lock key exists because earlier 84-key IBM PC keyboards did not have cursor control or arrows separate from the numeric keypad. Most earlier computer keyboards had different number keys and cursor control keys; however, to reduce cost, IBM chose to combine the two in their early PC keyboards. Num Lock would be used to select between the two functions. On some laptop computers, the Num Lock key is used to convert part of the main keyboard to act as a (slightly skewed) numeric keypad rather than letters. On some laptop computers, the Num Lock key is absent and replaced by the use of a key combination.[1]

Since Apple keyboards never had a combination of arrow keys and numeric keypad (but some lacked arrow keys, function keys, and a numeric keypad altogether), Apple has keyboards with a separate numeric keypad but no functional Num Lock key. Keyboards manufactured by Apple will instead use a Clear key but not all Apple manufactured keyboards will be provided with it.[2]

Keys affected by Num Lock! Key on
Numeric Keypad! Num Lock On! Num Lock Off
11End
22Down Arrow
33Page Down
44Left Arrow
55does nothing (usually)[3]
66Right Arrow
77Home
88Up Arrow
99Page Up
00 (zero or comma) Insert
.. (dot) or , (comma)Delete

References

ow Num Lock WorksNumeric Mode: When Num Lock is turned on, the keys on the numeric keypad can be used to input numbers and mathematical symbols, much like a calculator. This mode is particularly useful for data entry tasks that involve a lot of numerical input.

Cursor Control Mode: When Num Lock is turned off, the numeric keypad functions like the arrow keys. This allows the user to navigate the cursor around the screen using the numeric keypad.

Typical Keys on Numeric KeypadNumbers 0-9: Standard digits for numerical input.

Decimal Point: A dot used for decimal numbers.

Mathematical Operators: Includes addition (+), subtraction (-), multiplication (*), and division (/).

Enter Key: Allows for quick entry of numbers or commands.

LED IndicatorMost keyboards have an LED indicator light that shows whether Num Lock is activated. This helps users quickly see the current state of the key without having to press it.

Common UsesData Entry: Ideal for accountants, cashiers, and others who frequently enter numerical data.

Gaming: Some games use the numeric keypad for additional controls.

Navigation: Useful for controlling the cursor in text documents or spreadsheets when Num Lock is off.

Whether you’re crunching numbers or navigating through documents, Num Lock ensures that the numeric keypad serves dual purposes, enhancing your efficiency and functionality.

Notes and References

  1. Web site: Press Fn+F8, F7, or Insert to enable/disable numlock. 2023-09-18. Lenovo Support. en.
  2. Web site: Use your Apple Keyboard in Windows with Boot Camp. 2022-01-16. Apple Support. en.
  3. Web site: keyboard - Has the '5' key on the numeric keypad ever had an alternate function in hardware?. 2022-01-16. Super User.