To begin with, Mathematics does not have a clearly described, globally approved meaning. However it is safe to say that anything that researches the connections between qualities, variables, structure and change, is mathematics. Mathematics is not a concrete factor, but actually a subjective idea. There are a good many techniques of showing mathematics; the one you are probably most acquainted with is the base ten Arabic format that spreads throughout science right now. The base, the signs, the structure and the techniques used to show mathematics can all be drastically different and yet, it is still mathematics. Other cultures have created other techniques of showing mathematics and if we ever run into alien intelligence, it is likely that they will use a different program than we do. But the program is not the point. This is because mathematics is the appearance and quantification of primary sensible ideas and then it develops on those sensible ideas to form progressively complicated ideas. It is, however, entirely a sensible development.
The crazy thing about logic is that the advanced things are complicated, the advanced things are easy, and the primary things are greatly more complicated than the advanced things. This is one purpose why explaining mathematics is challenging. ‘Mathematical Logic’ and ‘Set Theory’ are both essential areas of the viewpoint that forms the base of mathematics, but both of those are regarded part of mathematics and therefore are rationally incorrect explanations for mathematics.
You could think of this as a sensible inconsistency with reasoning itself. The confusing thing is that even though overall sensible evidence is challenging as per Münchhausen’s Trilemma, it is still usually fairly easy to figure out if a sensible line is legitimate or not, particularly in mathematics. Mathematics is the most essential kind of reasoning possible (in technology anyway) and therefore it is easy to reason that mathematics is the best way of expressing the universe.