Ключевые слова: back, back to school, background, blackboard, book, brain, brainstorm, chalkboard, chemistry, child, childhood, clever, concept, creative, cute, development, discovery, education, formula, fun, future, girl, hand, happy, kid, kids mathematics, knowledge, learning, little, math, mathematics student, mental, mental mathematics, occupation, physics, primary, pupil, school, schoolgirl, science, small, smart, smiling, student, success, successful, thumb, to, up,