I am a grad student in mathematics at the University Augsburg, Germany. Since I am still filling up this website with content there might not be that much stuff here at the moment. Anyway, I hope you can find something useful. Feel free to send me a message.
A set of mathematical riddles including dwarves. It is written in German and the difficutly ranges from "Well-known and standard" to "I don't know anybody who knows a complete answer". A star means that the problem is more difficult. Illustrations are by Carina Willbold and Almut Tröller.
These are notes for a short course on general relativity for high school students at the math summer camp 2016 in Violau. Anyway they are here by request and were never made for publication. I will add links to much better documents online whenever I find them. However, this is a somewhat involved topic for younger students so if anybody has ideas or scripts explaining GR to high school students, please send me an email.
I helped founding the Matheschülerzirkel Augsburg, an organization offering free advanced math courses to high school students in Augsburg and Bavaria. We offer math circles, a large math summer camp as well math olympiads. You can find the website here. The following are a few scripts that I created for this purpose, unfortunately most are in German. However, some of them are not yet finished and a few others we modified quite heavily in order to use them as correspondence letters. Anyway, have fun!
During my time at MSU I gave a course on Euclidean geometry for prospective high school teachers. The following are a few sample homework sheets. If you are interested in solutions or exams just let me know.