Ключевые слова: 100, abstract, account, background, banner, blackboard, blank, blankness, board, business, buy, calculate, calculating, chalk, chalkboard, cipher, classroom, compute, consideration, count, credit, cypher, deduction, design, discount, double, economy, education, finance, financial, flat, glass, graphic, hundred, icon, ideal, interest, investment, lacunae, math, mathematics, money, numerous, pattern, percent, percentage, perfect, perfection, perfectly, plank, planning, price, profit, promotion, proportion, rate, retail, revenue, sale, savings, scale, school, schoolroom, selling, shape, shopping, sign, statistics, symbol, tax, teaching, texture, write,