People tend to think of abacuses (or is it abaci) as archaic devices with no relevance today, except as an aid to teach children basic arithmetic. For the most part, they would be right.

There is, however, a lot of value the abacus can give even in this modern computer age. Not only can experienced abacus users do amazingly quick calculations with them, but the methods used to calculate can be useful for computers too.

One example is with calculating a square root, which Martin Guy discusses in a paper he wrote in 1985.

He details how the algorithm he found in the book, The Fundamental Operations in Bead Arithmetic: How to Use the Chinese Abacus by C.C. Woo, to calculate the square root using an abacus, when implemented as a computer routine, is actually several times faster than many standard computer implementations of the square root function at that time.

I think it would be interesting to see if now, 25 years later, this routine would still be faster than standard square root functions.

It is incredible that a centuries old computing device can still have an impact even today.