Ключевые слова: balance, black, business, button, calculating, calculator, checkout, click, code, count, countdown, counter, counting, customer, digit, display, equipment, figures, finance, gray, hand, held, industry, instrument, isolated, key, machine, mathematic, mathematical, measurement, metal, number, object, occupation, push, silver, single, small, sport, store, subtraction, tally, technology, voting, white,