First of all, I think it's a poor example. A full circle in degrees is an integer while in radians it's not even a fractional number (it's an irrational number)

First of all, I think it's a poor example. A full circle in degrees is an integer while in radians it's not even a fractional number (it's an irrational number)! Also, I don't get the thing about fractions. Decimal numbers are fractions as well.