<p>this thread is painful, did you all skip the section on convergence of infinite series in calculus? just because there is an infinite number of things doesn’t mean we can’t make an exact calculation, in fact that is EXACLTY what calculus is based on. the number .9999…=1, it is simply a matter of convergence. this doesn’t mean .99=1, or .999=1, or .99999999999999999999999=1, it only means .999…=1. it isn’t an approximation, it is a well defined mathematical expression that is exactly true.</p>