Pi is definitely not a fractional number... I don't think it's cheating at all, multiplication on the naturals is repeated addition, that's not the case for the reals.
And that's my point, basically - By the time we're discussing real numbers, we need multiplication as an operator, because we're discussing ratios already.
While it's true, it obscures the fact that pi is defined as a fraction: Circumference/Diameter.
That this fraction cannot be represented as a numeric fraction is one of the great insights of early mathematics.