No real study, I'm just going to school again. Something like high school for adults in the evening. Right now in math we deal with this: https://en.wikipedia.org/wiki/Function_(mathematics) and especially this: https://de.wikipedia.org/wiki/Kurvenschar
On the English wiki page it looks different.
It's not too difficult to solve those arithmetic test papers, as long as I understand the question. Math-German is so difficult for me. I never understand what they are saying in first place.
But when I don't forget to breathe (in... ... and out... ... and in... ... ...) it's possible to stumble through the exam. My teacher says: "Always keep your nose (head) above water."