Ключевые слова: addition, angry, arithmetic, asking, baby, board, business, child, class, complexity, concept, confusion, counting, creativity, cry, curly, division, doubt, education, gesture, girl, hair, head, idea, kid, leader, learn, mark, mathematics, mind, multiplication, paper, person, pupil, question, rainbow, school, schoolchild, sign, smart, solution, sticker, student, study, subtraction, success, symbol, think, thoughtful, unusual, young,