The Abacus

1
The Abacus

• By Rosa Kemp

2

The Basics

• abacus
• Plural-abacuses or abaci
• Abacus is a Latin word that has its origins in
  the Greek words abax or abakon (meaning table
  or tablet) which in turn, possibly originated
  from the Semitic word abq, meaning sand
• The abacus is a mechanical aid used for counting
  it is not a calculator in the sense we use it
  today

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A Timeline of Human Counting Devices

• Early man counted by means of matching one set of
  objects to another set
• Ex. Stones and sheep
• 3000BC-an early form of the abacus originates in
  the Orient that has beads strung on wire
• 1000BC-Counting boards develop in China
• 300AD-Chinese begin to use the abacus for
  computations
• 500AD-Europeans begin to use the abacus

http//www.ideafinder.com/history/inventions/abacu
s.htm
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Progression of the Abacus

• Dust abacus- early Mesopotamia
• Line abacus- Egypt, Rome, India

• Grooved abacus- Rome

• Chinese abacus- Ming Dynasty (1368)

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Positional Notation

• A single object standing for a collection of
  objects
• Numeral system in which each digit is related to
  the next by a constant multiplier called the base
• The value of each digit position is the value of
  its digit multiplied by a power of the base
• The power is determined by the digit's position

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Anatomy
http//www.ee.ryerson.ca/elf/abacus/intro.html
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Using the abacus

• Counting
• After 5 beads are counted in the lower deck, the
  result is "carried" to the upper deck after both
  beads in the upper deck are counted, the result
  (10) is then carried to the left-most adjacent
  column
• The right-most column is the ones column the
  next adjacent to the left is the tens column and
  so on

8
The Abacus Today

• The abacus is still in use today by shopkeepers
  in Asia and "Chinatowns" in North America
• Blind children are taught to use the abacus where
  their sighted counterparts would be taught to use
  paper and pencil to perform calculations
• One particular use for the abacus is teaching
  children simple mathematics and especially
  multiplication the abacus is an excellent
  substitute for memorization of multiplication
  tables, which can be difficult for young children
  
• The abacus is also an excellent tool for teaching
  other base numbering systems since it easily
  adapts itself to any base

9
Soroban

• Soroban- the Japanese version of the abacus
• Anzan-the use of an imaginary soroban to do
  calculations

http//www.youtube.com/watch?vPx_hvzYS3_Y