Ключевые слова: abacus, accounting, accounts, addition, ancient, antique, archaic, bead, brown, business, calculation, calculator, closeup, count, education, equals, equipment, finance, frame, immemorial, math, mathematic, mathematical, number, numbering, numeration, old, primitive, retro, series, sliding, subtraction, symbol, tool, used, vintage, wood, wooden, work,