Sony PCG-F540 Primary User Manual page 33

Your keyboard is very similar to a typewriter's, but the keyboard has
additional keys that perform specific computer-related tasks.
Numeric keypad
area
Navigation keys
Correction keys
Function keys
Escape key
Print Screen key
Contains the keys found on a typical calculator. Use the
numeric keypad area to type numbers or to perform
mathematical calculations such as addition and
subtraction. Note that you must press the Num Lock key
to activate the numeric keypad. (When you do so, the
Num Lock light will be on.)
Several keys are devoted to moving the cursor on the
screen.
The Insert, Back Space, and Delete keys enable you to
make corrections in your documents.
The twelve function keys along the top of the keyboard
are used to perform designated tasks. For example, in
many applications, F1 is the Help key. The task associated
with each function key may vary from one application to
the next.
The Esc (Escape) key is used to cancel commands.
The Print Screen key takes an electronic snapshot of the
screen and places it in the Windows Clipboard. You can
then paste the screen shot into a document and print it.