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What is an abacus? Well, an abacus is a device used for addition and subtraction,and the related operations of multiplication. There are two basic forms of the abacus: a specially marked flat surface used with counters ( also called counting table), or a frame with beads strung on wires ( called a bead frame). |
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Even though people don't really use a counting table today, they have over 2,000 years of documented use! One of their earliest forms was of a simple stone slab with incised parallel lines. The lines marked the place values. But the only real difference between the early and later forms is the direction of the place values( horizontal or vertical). |
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It is very important to distinguish the early abacuses (known as counting boards) from the modern day abaci. The counting board is a piece of wood, stone or metal with grooved or painted lines between which beads, pebbles or metal discs were moved. The abacus is a device, usually made out of wood, and having a frame that holds rods with beads that slide freely on the rods. |
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Both the abacus and counting board are mechanical tools used for counting. They are not really like the calculators that we use today. The abacus is different than a calculator because the person using the abacus has to be able to perform calculations in their head and then uses the abacus as a means to keep track of sums, borrowing, carrying, etc; |
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