Sorry, no definitions found. You may find more data at abaci.


Sorry, no etymologies found.


  • Fibonacci's 1202 manuscript "Liber Abaci," the foundation of modern arithmetic, contains a number of magic tricks, including several versions of the famous three-object divination, wherein a spectator mentally selects one of three objects and the magician correctly identifies the spectator's choice.

    Pick a Card, Any Card

  • More than any other book, the Liber Abaci introduced the Indian system to the West.


  • Professional abacus operators felt threatened by the easier method, for one thing, and the timing of publication was not perfect: the Liber Abaci appeared during the period of crusades against Islam, with the clergy suspicious of anything with Arab connotations.


  • Realizing that they were much better than Roman numerals, Fibonacci wrote a book about the decimal place value system called the Liber Abaci, published in 1202.


  • The Mathematician Leonardo of Pisa, more commonly known as Fibonacci, wrote a book called Liber Abaci, The Book of Abacus, in 1202.

    Archive 2007-03-01

  • He used what is now known as the Fibonacci sequence - actually a pre-6th-century Indian concept - as an example in his famous and apparently brilliant book about math, Liber Abaci, or Book of Calculation, which is why we have it now.

    Archive 2007-09-01

  • Corporate Connections: Abaci aren't as popular as they once were, but you can still buy one from companies like American Science and Surplus or Advance Engineering.

    No. 2 The Abacus

  • Abaci are still widely used in the East, with slight variations in design--such as the number of beads and wires, and the presence of dividing beams--occurring between countries.

    No. 2 The Abacus

  • [534] "Incipit liber Abaci a Leonardo filio Bonacci compositus anno 1202 et correctus ab eodem anno 1228."

    The Hindu-Arabic Numerals

  • Peter Abaci, M.D. Chronic pain specialist published a call to action for a "cultural transformation in the way clinicians and the public view pain and its treatment."

    The Full Feed from


Log in or sign up to get involved in the conversation. It's quick and easy.