Ключевые слова: blackboard, caucasian, celebrating, chalk, chalkboard, cheerful, child, classroom, clever, concept, counting, digits, education, elementary school, equation, exam, first grader, formula, girl, grade, hands up, happy, intelligence, kid, knowledge, learning, lesson, math, mathematics, numbers, one, pensive, people, person, practise, primary school, problem, pupil, school, schoolchild, schoolgirl, smart, solving, student, studying, summation, test, thinking,