Mathematics 50 Study and teaching 26 Dissertations, Academic (Ph.D) 11 Thesis (Ph.D)-Education 11 Mathematics-Study and teaching (Secondary) 8 Mathematics-Study and teaching 7 Study and teaching (Elementary) 7 Mathematics--Study and teaching 6 Mathematics-Study and teaching (Elementary) 6 Study and teaching (Secondary) 6 History 5 Mathematics--Study and teaching (Secondary) 4 Acalculia in children 3 Education 3 Effective teaching 3 Mathematics--Study and teaching (Elementary) 3 Mathematics-Study and teaching (Primary) 3 Problem solving 3 Psychological aspects 3 Study and teaching (Higher) 3 Study and teaching (Middle school) 3 Study and teaching (Primary) 3 Activity programs 2 Algebra 2 Communism and education 2 Competency-based education 2 Congresses 2 Curriculum planning 2 Group work in education 2 Individualized instruction 2