Ключевые слова: algebra, analytic, back, board, chalkboard, chart, classroom, college, creative, crosscut, design, doodle, drawing, drawn, education, equation, formula, genius, graph, hand, icon, knowledge, learn, math, mathematical, mathematics, pattern, physic, physical, physicist, physics, proposition, right angle, school, science, sign, sketch, solution, student, study, subtraction, symbol, task, teacher, test, texture, theorem, typography, university,