The Mathematical (n.) is that "about" things which we already know and do not get from them but bring with us — as no three chairs, apples or cats can tell us what "three" is.
The Mathematical (n.) is the basic stance in which we take things as already given to us, and as they must and ought to be given — the presupposition behind all knowledge of things.
The Mathematical (n.) is, in the sense of learning what one already knows, the fundamental presupposition of 'academic' work. Plato's words over the academy are nothing but a hard condition and clear circumscription of work.
The Mathematical (n.) is that 'about' things which we really already know (i.e.) the body as bodily, the plant-like of the plant, the animal-like of the animal, the thingness of the thing. We do not first get something out of things, but, in a certain way, we bring it already within us.
The Mathematical (n.) is the idea that, for example, in grasping the number three (as in the recognition of their being 3 chairs over there) as such, we only expressly recognize something which, in some way, we already have. This recognition is genuine learning.