Activities/Terminal
Terminal provides a Bash shell command line, with access to all of the usual cryptic Unix commands, which are generally considered beyond the capabilities of elementary-school children. However, there are always exceptions. A good starting point is Introduction to the Gnu/Linux Command Line from FLOSS Manuals.
Midnight Commander is a character mode file manager that can run directly in Terminal. Install it with
sudo yum install mc
Be sure to configure Lynx-like motion in Options:Configuration. This lets you navigate the directory tree with the cursor keys.
The user can configure Sugar either in the UI, or using sugar-control-panel from the command line.
One of the most requested commands is
setxkbmap keyboard
where keyboard can be us (US English), dvorak, fr (French), and so on. See olpc:Keyboards for more.