This is a read-only archive of the inkscapeforum.com site. You can search for info here or post new questions and comments at 
Although not all documentation makes it clear, the 5 is the one on the numeric keypad, not the one on the top row of keys.
If you do still want to change it (e.g. if you're on a laptop that doesn't have a separate numeric keypad), you can modify the keyboard shortcuts from Edit > Preferences > Interface > Keyboard Shorcuts. Toggle is in the "View" section.