# The Abacus By: Ashley Margolis.

## Presentation on theme: "The Abacus By: Ashley Margolis."— Presentation transcript:

The Abacus By: Ashley Margolis

What is an Abacus An abacus is one of the first counting devices
It is used for addition, subtraction, multiplication and division It is a calculator used by manually sliding counters along rods Pullan, J.M.. The History of the Abacus. Great Britain: Hutchinson of London, 1968.

How is the Abacus used?

"Abacus Guide Book." Abacus. 18 Nov 2007 <http://www.tux.org/~bagleyd/AbacusGB.html>.

Helps kids learn basic number systems Helps kids understand barrowing and carrying in arithmetic Helps Kids understand combinations of five and ten Helps kids visualize the math and develops mental calculations "Abacus." 15 October November 1007 <http://www.smm.org/boghopper/Abacus.html>.

Unlike a calculator it can only be used for Addison subtraction, division and multiplication. Because counters are manually moved, its hard to tell if you make a mistake. Abacus." 15 October November 1007 <http://www.smm.org/boghopper/Abacus.html>.

Why does the Abacus exist?
Earliest counting device was the hand and fingers. When people started to count larger things used twigs and pebbles. Until numbers were used, people used many different types of counting devices and the Abacus was one of them. Fernandes, Luis. "A Brief History of the Abacus." Abacus, The Art of Calculating with Beads. 30 August Nov 2007 <http://www.ee.ryerson.ca:8080/~elf/abacus/history.html>.

Can every one use the Abacus?
Used by individuals who are blind or visually impaired. Gives blind students a tool to solve math problems that are long and difficult. Allows these students to complete problems as fast as their peers. Used switches instead of beads "Abacus Guide Book." Abacus. 18 Nov 2007 <http://www.tux.org/~bagleyd/AbacusGB.html>.

Different types of Abaci
Chinese Russian Japanese Roman Called a Soroban Called a Suanpan Has two beads on top of beam for weights and measures. In wood frame, 2 beads on top and 5 beads on the bottom Is considered the first pocket calculator. Called a Schoty 10 beads on each rod Start by moving all the beads to the right side. Move beads from right to left.