The preparatory online course of Technische Universität Berlin and the VE&MINT project serves those interested in studying a technical subject at university level as a preparation and for assessing their competences in mathematics.
The course covers school mathematics from calculus to geometry as required for starting a scientific or technical career at a German university. Completing the course is no formal requirement for entering a university, it is totally voluntary. The idea is to help you to brush up your maths skills.
Math for Refugees is free of cost and no registration is required.
It is available both in German and in English. A button allows you to switch the language anywhere in the course.