If you are used to using a standard keyboard on a PC, you have probably seen the Number Lock button in the top, left corner of the number pad. This button either allows you to use the number pad as numbers or disables the numbers and allows you to use the keys as arrows. The standard Macintosh keyboard does not have a Number Lock key, nor does it have arrows on the Number Lock number pad. Mac does have a feature, however, that will lock the number pad and allow you to control the mouse arrow as if you were using arrows on the number pad.
Click on the Apple logo and select "System Preferences." Then, select "Universal Access" in the System category.
Click on the "Mouse" tab. Select "On" next to "Mouse Keys." Pressing the numbers on the number pad will move the mouse as if the numbers were arrow keys. The number 8 moves the mouse up; 2 moves the arrow down; 4 moves the arrow to the left; and 6 moves the arrow to the right.
Click on "Press the Option key five times to turn Mouse Keys on or Off" to enable the shortcut for essentially turning on and off Num Lock. Close "System Preferences."
Press the "Option" key five times. Mouse keys will be enabled. Pressing the numbers on the number pad will move the mouse.
If you are using a Mac keyboard on Windows, such as through Bootcamp, you can turn the Number Lock on or off by pressing the “Clear” button.