Ключевые слова: algebra, background, black, blackboard, board, book, calculate, calculation, class, college, complex, concept, drawing, education, equation, exact, exam, examination, formula, geometry, graph, handwriting, homework, knowledge, learn, learning, lesson, math, mathematical, mathematics, number, paper, pattern, pencil, physics, problem, research, school, science, sign, solution, study, studying, symbol, teacher, test, theory, trigonometric, trigonometry, white,