History%20of%20abacus

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History of abacus
The abacus' history started ca. 2600 years ago in
Madagaskar. There to count the amount of
soldiers, every soldier had to pass a narrow
passage. For each passing soldier a little stone
was put into a groove. When ten stones were in
that groove they were removed and one stone was
put into the next groove.
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Counting soldiers
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Mutation of grooves and stones
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Development of soroban
In 607 the japanese regent Shotoku Taishi made a
cultural approach to China. The chinese suan-pan
comes to Japan and became optimized by Taishi by
removing one of the upper balls. Since 1940 the
new soroban with only four lower balls is used.
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Roman abacus
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Calculating on tables
This structure was found on tables, boards and on
kerchiefs.
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Gelosia procedure of writing calculation
0
5
6
0
8
8
56008
123 456
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Napier Bones
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Calculating with Napier Bones
239 8
2
1
9
1