Samsung N640 User Manual page 13

To clean the computer keyboard, use slightly damp cotton swabs. Scrub the key
and the surface around the keys.
Do not allow liquid to drip into the keyboard or you may
damage the keyboard.
Using the Embeded Numeric Keypad
Your keyboard includes a numeric keypad, which is a group of keys that you can
set to type numbers and mathematical symbols, such as the plus sign (Figure 7). A
number or symbol on the right corner of each keypad key shows its numeric
function.
Figure 7. Numeric Keypad
Press <Num Lock> to turn on the embedded numeric keypad. The numeric
functions of the keypad are enabled and the Num Lock light turns on. (See " System
Status Lights" on page 18 for the location of the Num Lock light.)
While the numeric functions are enabled, you can temporarily return a key to its
normal function by pressing <Fn> and the key. For example to type the letter m,
press <Fn+m>.
To turn the numeric keypad off, press <Num Lock> again. The Num Lock light
turns off.
Using the Keyboard 13