I have just uploaded a first draft of my own elaboration on the traditional methods described by Knott for obtaining roots. Focusing mainly on cube roots, I offer several examples including obtaining four digits extending to 7-8 on a 13-rod abacus as anticipated in a previous post. I hope to finish writing it over the next few days.
The following list corresponds to the content of jccAbacus Web as of today. From now on, the current status of the Web will appear on an accessory page on this blog.
Ancient abacuses, both Japanese style (soroban) and Chinese style (suanpan), used to have five beads on the lower deck even though this is unnecessary from the point of view of representing decimal numbers.
What was the purpose of this additional fifth bead?
We have to look for the answer in ancient books.
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| Pánzhū Suànfǎ illustration showing the use of the 5th lower bead |
Sir Isaac Newton A non-traditional technique Square, cube and fifth roots can be solved on the abacus using Newton's method. It is not...
