teaching aids 1,118 physics 57 mathematics 57 English language 34 chemistry 34 analytical chemistry 33 civil engineering 30 more ... German language 28 examples 28 electrotechnics 21 building constructions 19 technology 19 geodesy 18 computers 18 teaching 18 controlling 18 economy 16 general chemistry 16 programming 16 mechanical engineering 15 physical chemistry 14 classical mechanics 14 programming languages 14 engineering 14 inorganic chemistry 13 management 13 mathematical statistics 13 materials 13 circuits theory 13 teaching methods 13 less ...