http://www.abacushome.info Articles and Information on the Abacus Wed, 30 Apr 2008 17:26:43 +0000 http://backend.userland.com/rss092 en Counting boards are the earliest known form of a counting device (excluding fingers and other very simple methods). They were made from natural material such as stone or wood, and the actual counting was done on the board with beads, pebbles, or even colored sand. Not many of ... http://www.abacushome.info/the-salamis-tablet/ When using a counting board or abacus the rows or columns often represent nothing, or zero. Since the Romans used Roman numerals to record results, and since Roman numerals were all postive, there was no need for a zero notation. But the Romans clearly knew the concept of zero ... http://www.abacushome.info/the-roman-abacus-inference-of-zero-and-negative-numbers/ The normal method of calculation in ancient Rome was by moving counters on a smooth surface/table. Originally pebbles, calculi, were used. Later, and in medieval Europe, jetons were manufactured. Marked lines indicated units, fives, tens, etc. as in the Roman numeral system. This system of 'counter casting' continued into ... http://www.abacushome.info/the-roman-abacus/ This software allows you to practice the ancient way of calculating. Styled after the classic abacus, slide the beads up and down using your mouse. As an added feature, enter a number and watch the beads move into place. Instructions are included. - License: Free to try; $12.00 ... http://www.abacushome.info/abacus-2-abacus-simulation-software/ HOW TO USE A CHINESE ABACUS: A step-by-step guide to addition, subtraction, multiplication, division, roots and more by PAUL GREEN [Author] Book Description This book will teach you step-by-step how to perform addition, subtraction, division, multiplication, square roots and cube roots on a Chinese abacus. It also explains ... http://www.abacushome.info/how-to-use-a-chinese-abacus/ The Abacus: The World's First Computing System: Where it Comes From, How it Works, and How to Use it to Perform Mathermatical Feats Great and Small (Paperback) by Jesse Dilson (Author) Book Description The abacus is as useful and efficient a machine today as it was when it was first created centuries ago. ... http://www.abacushome.info/the-abacus-by-jesse-dilson/