Summary of How the Embedded Numeric Keypad Functions

Legending: The numeric keypad numbers are legended on the top of the keycap in a blue color on the top right-hand corner of the keycap. The Navigation Keys are not legended but are supported as described below.

To Activate the Numeric Keypad:

Press and release the NumLock key once (i.e. a toggle). The green light at the top right hand corner of the keyboard labeled Num Lock will turn on.
To Deactivate the Numeric Keypad: Press and release the NumLock key once (i.e. a toggle). The green light at the top right hand corner of the keyboard labeled Num Lock will turn off.
With NumLock On: The keypad will generate numbers if the NumLock is active. If you press and hold the Fn (Function) key at the same time as NumLock is active, the numeric keypad will revert to the normal keyboard (i.e. letters).
With NumLock Off: Most computers will boot up with NumLock off, and in this case, the numeric keypad will perform its normal keyboarding functions. The navigation keys can be accessed at any time by holding down the Fn (Function) key and pressing the appropriate key on the embedded numeric keypad.
WHAT THIS MEANS  
To Get Numbers Toggle Access (Press NumLock and Release)
To Get Navigation Shift Access (Press Fn and Hold it Down)