It’s pronunciation is “a-buh-kuhs.”īecause the abacus is one of the first calculators created, its origin may predate the historical record. The abacus is believed to have been invented between 2,700 BC and 300 BC.Īn abacus is a calculating tool that’s been used for centuries and is still popular in many countries. The exact date of the invention of the original counting frame is unknown. patent # 4,037,200.Ībacus Explained - Everything You Need To Know FAQs (Frequently Asked Questions) He was also a member of the National Federation of the Blind.Ĭramer invented several devices, including a “Braille display switching matrix and circuit utilizing the same,” U.S. In 1952, he was employed by the Kentucky Division of Rehabilitation Services for the Blind. After being employed briefly at Kentucky Industries for the Blind, Cramer was a piano technician for 10 years. In his early years, he crafted and sold plastic jewelry. It can be used to perform addition, subtraction, multiplication, and division.Ĭramer was blind from childhood. The device is considered to be a valuable teaching tool for visually impaired students. It measures 6 1/8” x 3 1/4” and the bead diameter is 3/8”. This inexpensive, 13-rod abacus features a red felt backing which prevents beads from slipping during calculations. Shortly thereafter, the American Printing House for the Blind began selling the device, and they continue to sell it today. The Cranmer abacus is a modified version of the Japanese abacus or sorobon. The two possible binary digits are 0 and 1, but they are also described as low and high, which are the two possible positions for beads on an abacus. Binary digit, the numbering scheme used to encode and decode digital messages, is based on an abacus design. The abacus is also an ancestor of the modern calculator and computer. This origin, whether in Ancient China or Babylon, has been used throughout history and is continued to be used as a convenient calculator for commercial transactions. Abacus: Historical SignificanceĪs commercial transactions became more complicated, a calculating tool was essential to make quick calculations and avoid errors. It helps ensure quick calculations when working with large numbers and makes the calculation process visible to both buyer and seller or teacher and student.

This counting frame allows individuals to track, add, subtract, multiply, and divide numbers easily. You can then push additional beads from the bottom or, if available, from the top to count up to nine in that place value. Pushing one bead from the top row to the center counts as five. Many designs have four or five beads on a bottom row, with one to five beads on the top row. Starting either with the tens place or a decimal place, increasing from right to left. The idea of this counting frame is that each rod represents a sequential place value. Ancient devices used marble or stone parts. Most abacuses are made of a frame with wood rods and beads. It’s a fairly straightforward calculator that is still used in many countries in schools or markets for counting.

They should now read 4, blank, and 8, making your answer 408.The woman in this illustration is Typus Arithmeticae, considered the “muse of arithmeti.” Abacus: How It Workedĭespite its long history and unknown inventor, the abacus has worked basically the same way throughout the centuries. Record the product of the last two digits 4 and 2 (8), in the last of the answer columns.Since you're adding a 4 to a 6 in that column, carry one bead over to the first answer column, making a 4 in the seventh column (four beads from the bottom section pushed up to center bar) and a 0 in the eighth (all beads in their original starting position: the top section bead pushed up, bottom section beads pushed down). When you multiply the 4 and the 1, add that product (4) to the eighth column, the second of the answer columns.Push one bead from the upper section down, and one bead from the lower section up. Next, multiply the 3 and the 2, recording their product in the eighth column.Push three beads up in that seventh column. First, multiply 3 and 1, recording their product in the first answer column.For the problem 34 x 12: X Research source You will keep moving beads on the right hand portion of the abacus as you multiply the individual digits. Start recording in the first answer column, after the blank one for the “=” sign. Record the products in the correct order.

Abacus row