The article deals with the infinity symbol as it is used in calculus courses. With such a usage in mind the infinity symbol is not a number and does not repres

The article deals with the infinity symbol as it is used in calculus courses. With such a usage in mind the infinity symbol is not a number and does not represent a number. The usage of the infinity symbol in calculus is merely a shorthand notation for a more complicated statement. Suppose that we have Lim x->5 f(x) = infinity What is meant by the use of the infinity symbol is that the limit is not bounded in the real number system. More specifically that given any large real number I can find a number d such that whenever |x - 5| < d then f(x) > M. Here the use of infinity is not meant to be as a number though making such an association is helpful to beginners in terms of visualizing what is going on. Students have trouble with the precise definition of being unbounded and so it's convenient to say "it's infinity" and treat the symbol as a number.