NEW YORK, N.Y.- Key parts of the Liber Abaci, the work that shaped the course of history by introducing Arabic numerals to the west, are to be sold at Bonhams New York on 22 June. They feature in a rare 15th century manuscript estimated at between $120,000-180,000 (£75,000 – 110,000). The Liber Abaci or Book of Calculation is by Leonardo Pisano Bigollo or Fibonacci, considered by many as one of the most talented western mathematicians of the Middle Ages. Fibonacci is widely credited with bringing the Hindu-Arabic numeral system to the western world. Within the text of the Liber Abaci, Fibonacci explains the benefits of Arabic numerals and the symbol for zero by applying them to the practical world of book-keeping, weights and measures, and trade. His theory popularized Arabic numerals by appealing to tradesmen and academics and eventually convincing the public of the superiority of the new numerals. It was Fibonacci&#