Ключевые слова: asian, background, blackboard, board, boy, caucasian, chalk board, chalkboard, challenge, class, classroom, college, concentration, creative, education, elementary, equations, formula, formulas, girl, indoors, intelligence, knowledge, learn, learning, male, man, mathematician, mathematics, person, physics, problem, professor, school, science, serious, smart, solution, student, studying, symbols, teach, teacher, thinking, university, wall, work, working, writing,