History of AbacusHistory of Abacus

By: Huy Do & Trinh HuynhBy: Huy Do & Trinh Huynh

OutlineOutline

History of abacusHistory of abacus Abacus lingo Abacus lingo Why use abacusWhy use abacus How to addHow to add How to subtractHow to subtract How to multiplyHow to multiply How to divideHow to divide

History of AbacusHistory of Abacus Abacus ? (personal calculator)Abacus ? (personal calculator)

- a device used for “+”, “-”, “x”, “/”- a device used for “+”, “-”, “x”, “/”

- does not require the use of pen & paper and good for any - does not require the use of pen & paper and good for any base number systembase number system

- derives from the Greek word ABAX – table or board covered - derives from the Greek word ABAX – table or board covered with dustwith dust

Most historians believe the abacus was first created in Central Most historians believe the abacus was first created in Central AsiaAsia

From there it spreads West to Europe, and East to China, and From there it spreads West to Europe, and East to China, and its neighboring Oriental countries its neighboring Oriental countries

““Modern” Chinese abacusModern” Chinese abacus

- appeared in China between the 12- appeared in China between the 12thth and 13 and 13thth century AD. century AD.

““Modern” Chinese abacus lingoModern” Chinese abacus lingo

12345678910111213

Why use Abacus?Why use Abacus?

Run by handRun by hand Simple to useSimple to use Operate for yearsOperate for years Teach you how to manipulate numbers Teach you how to manipulate numbers - how each digit relates to the others and use that knowledge to - how each digit relates to the others and use that knowledge to

do all the major operations - +,*,/do all the major operations - +,*,/ Let you learn all about the base ten systemLet you learn all about the base ten system Show you how to math in the decimal system and the binary Show you how to math in the decimal system and the binary

system system Can solve problems just as fast or even faster than a modern Can solve problems just as fast or even faster than a modern

electric computer.electric computer.

How does it work?How does it work? The first column is for unitsThe first column is for units The second column is for tensThe second column is for tens The third column is for hundredsThe third column is for hundreds And so on…And so on…

How to AddHow to Add8 + 58 + 5

How to SubtractHow to Subtract13 - 913 - 9

How to MultiplyHow to Multiply6 x 4 6 x 4

Feed 6 beads into abacus 4 Feed 6 beads into abacus 4 timestimes

How to divide How to divide 24 / 824 / 8

How many 8’s are there in 24How many 8’s are there in 24