Magic Keyboard with Numeric Keypad
The wireless Magic Keyboard with Numeric Keypad provides shortcuts for common functions, such as increasing the volume or screen brightness.
Turn the keyboard on or off. Slide the on/off switch on the back edge of the keyboard to turn it on 
(so green is visible) or off. If your keyboard isn’t recognized by your Mac Pro, connect it to your Mac Pro with the included USB-C to Lightning Cable to set it up, then disconnect the cable to use it wirelessly. Use the same cable to charge your keyboard.
Use function keys. The function keys on the top row provide shortcuts for these common system functions:
Brightness keys (F1, F2): Press
or 
to increase or decrease the brightness of the screen.
Mission Control key (F3): Press
to view what’s running on your Mac Pro, including all your spaces and open windows.
Launchpad key (F4): Press
to open Launchpad and instantly see all the apps on your Mac Pro. Click an app to open it.
Media keys (F7, F8, F9): Press
to rewind, 
to play or pause, or 
to fast-forward a song, movie, or slideshow.
Mute key (F10): Press
to mute the sound from the built-in speakers or 3.5 mm headphone jack.
Volume keys (F11, F12): Press
or 
to increase or decrease the volume of sound from the built-in speakers or 3.5 mm headphone jack.
Function (Fn) key: Each function key (on the top row) can also perform other functions. Hold down the Fn key while you press a function key to trigger the action associated with the key.
Tip: Press the Fn key twice to turn on dictation, which lets you dictate text wherever you can type it, such as in Messages, Mail, Pages, and many other apps. (Requires an external microphone, which is sold separately at apple.com and your local Apple Store.)
Set keyboard preferences. In System Preferences, click Keyboard, then click the buttons at the top to see the available options).
Use keyboard shortcuts. You can press two or more keys at the same time to quickly do things on your Mac Pro that you’d normally do with a trackpad, mouse, or other device. For example, press Command-C to copy selected text, then click where you want to paste the text and press Command-V. For a list of commonly used keyboard shortcuts, see Keyboard shortcuts on your Mac. If you’re new to the Mac, you might also be interested in Are you new to Mac?.