Transcript History of the Abacus ppt

History of Abacus
By: Huy Do & Trinh Huynh
Outline
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History of abacus
Abacus lingo
Why use abacus
How to add
How to subtract
How to multiply
How to divide
History of Abacus
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Abacus ? (personal calculator)
- a device used for “+”, “-”, “x”, “/”
- does not require the use of pen & paper and good for any
base number system
- derives from the Greek word ABAX – table or board covered
with dust
Most historians believe the abacus was first created in Central
Asia
From there it spreads West to Europe, and East to China, and
its neighboring Oriental countries
“Modern” Chinese abacus
- appeared in China between the 12th and 13th century AD.
“Modern” Chinese abacus lingo
13 12 11 10 9
8
7
6 5
4
3
2 1
Why use Abacus?
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Run by hand
Simple to use
Operate for years
Teach you how to manipulate numbers
- how each digit relates to the others and use that knowledge to
do all the major operations - +,*,/
Let you learn all about the base ten system
Show you how to math in the decimal system and the binary
system
Can solve problems just as fast or even faster than a modern
electric computer.
How does it work?
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The first column is for units
The second column is for tens
The third column is for hundreds
And so on…
How to Add
8+5
How to Subtract
13 - 9
How to Multiply
6x4
Feed 6 beads into abacus 4 times
How to divide
24 / 8
How many 8’s are there in 24