Help viewer: "The way the numeric keypad works depends on your computer, the particular keyboard you are using, the application you're working in, and whether the Num Lock key is engaged. Usually, the numeric keypad is used to enter numbers in a document, but in some applications you might be able to use the keypad to navigate (move around in) your document.
Press the Num Lock key to switch between the ways the numeric keypad functions.
If you have a separate numeric keypad on your keyboard, the Num Lock key is located in the numeric keypad. If you're using a portable, the Num Lock is a function key, marked Num Lock (F6). If your keyboard has a separate keypad but no Num Lock key, try pressing Shift-Clear.
Most PowerBooks have a group of keys on the keyboard that can function as the numeric keypad. To find the keypad, look for small numbers or symbols in the lower-right corner of keys on the right side of your keyboard. Press the Num Lock key (F6) to turn on the keypad. The green light glows on the Num Lock key when the keypad is active."
(please try the mac help before posting here)