Newton's method for roots on the soroban

 

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 a traditional method, but it is very old, so much so that it is also called the Babylonian method when it comes to square roots, although there is no evidence that it was actually used by the ancient Babylonians. What does matter is its effectiveness and the fact that it is very compact on the abacus.

The Radix Method

 How to obtain decimal logarithms and antilogarithms on the abacus

Cover from Robert Flower's
The Radix. A New Way of Making Logarithms
(London 1771)

Some problems require the use of logarithms for their solution; for example, complicated roots or time value of money (TVM) problems. With the abacus, as in written calculation, there are two possible approaches:

Content of jccAbacus Web

 Summary of what was published up to May 2021

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.