Ключевые слова: back to school, childhood, children, classmates, education, educational, elementary, emotions, friends, friendship, geometry, girls, homework, kids, knowledge, knowledge day, lesson, math, mathematical, mathematics, maths, measure, measurement, measuring, primary, pupils, sad, school, school age, schoolchildren, schoolers, schooling, september 1, sisterhood, sisters, teenage, teenagers, teens, triangular rulers, tweens, unhappy, yellow background,