Using the CAS View

Enter	Evaluate input
;	Suppress output
Ctrl + Enter	Evaluate in numeric mode
Alt + Enter	Check input
Escape	Clear input
$	Previous output (dynamic reference)
#	Previous output (static reference)
$3	Output of 3rd cell (dynamic reference)
#3	Output of 3rd cell (static reference)
F1	Help for current command
TAB	Show next matching command

Auto-Completion of Commands
After typing the first two letters of a command
GeoGebra will complete the command for you.

Enter	Accept proposed command
Another letter	Adapts proposed command