Ключевые слова: 1, 2, 3, 4, 5, 6, 7, 8, 9, accuracy, adding, banking, business, button, calculator, calculus, counting, depression, dividing, economic, equality, equipment, exchange, figures, finance, financial, global, growth, home, investment, keypad, mathematics, multiplication, note, number, object, panel, pen, printed, problems, rate, receipt, savings, shares, single, solar, stationery, stocks, tax,