So a kind of difficulty level or branch of mathematics is not caused by a type or a branch of mathematics itself, but due to the difficult and complex phenomena of solution grown or closed sought by the formulation with the use or the type of mathematics is a branch.

On the various physical phenomena observed in the volatile, for example, the number of people across the country, not the type of need or a branch of mathematics that sophisticated. Aritmatics have enough ability to find the solution (number of population) with high enough accuracy.