Ключевые слова: arrow, background, blond, board, casual, caucasian, chalk, chalkboard, child, childhood, children, class, classroom, closeup, concentration, cute, digit, education, eyeglass, eyewear, formula, girl, green, hair, hand, holding, indoors, kid, knowledge, leader, little, mathematics, number, one, people, person, pretty, room, school, schools, side, small, smart, solution, solving, standing, study, studying, text, writing,