Chris,
The simple way to look at this is that you want k parts where k=2n.
Then some people get 2 parts and some get 1.
So in your example, divide the circle into 9 parts. Give four people 2 parts each, and one person one part.
This shift in how you represent the problem lets you use your current processes for a whole number to address any fractional division.
Walter Whiteley
