Definitions for keypadˈkiˌpæd
Random House Webster's College Dictionary
a small panel of numeric and other special keys, as on a computer keyboard.
Origin of keypad:
computer keyboard, keypad(noun)
a keyboard that is a data input device for computers; arrangement of keys is modelled after the typewriter keyboard
A small board with keys primarily used for tactile input into a machine.
Many laptop computers have special function keys which turn part of the alphabetical keyboard into a numerical keypad.