Spot on! Either that or pi is a symbol and we use symbolic algebra. Just convert to the result in floating point at the last minute. Ironically my calculator

Spot on! Either that or pi is a symbol and we use symbolic algebra. Just convert to the result in floating point at the last minute. Ironically my calculator quite happily manages rational form including PI as a constant: http://h41111.www4.hp.com/calculators/uk/en/scientific/smartcalc300s.html http://h41111.www4.hp.com/calculators/uk/en/scientific/smart...