Ключевые слова: algebra, arithmetic, background, calculate, calculation, calculator, calculus, child, childhood, college, color, education, elementary, equation, equations, exam, exercise, formula, geometry, girl, homework, kid, knowledge, learn, learning, lesson, math, mathematical, mathematics, notebook, number, paper, pen, pencil, preschool, problem, resolve, school, science, scientific, solve, spiral, student, study, studying, subject, symbol, teach, university, write,