An infinitely small quantity is defined as a one-dimensional quantity of finite length but with sizes of space, while an infinitely great quantity is reached by the superposition or accumulation of infinitely many finite quantities, by the way of the change in direction. The change in direction indicates that there is a jump from a finite quantity to infinitely many finite quantities (infinitely great). The form of the manifestation of the infinitely great is one quantitative continuum that cannot be operated by any algorithms and all parts of space we see is this one quantitative continuum. .Any value are this single quantitative continuum that indicates the infinitely great and compresses any quantities outside of it to nothing. As a result, the infinite exact value of a circumferential length (π) has been obtained here.