English

A Spigot-Algorithm for Square-Roots: Explained and Extended

Discrete Mathematics 2023-12-27 v1

Abstract

This work presents and extends a known spigot-algorithm for computing square-roots, digit-by-digit, that is suitable for calculation by hand or an abacus, using only addition and subtraction. We offer an elementary proof of correctness for the original algorithm, then present a corresponding spigot-algorithm for computing cube-roots. Finally, we generalize the algorithm, so as to find rr-th roots, and show how to optimize the algorithm for any rr. The resulting algorithms require only integer addition and subtraction.

Cite

@article{arxiv.2312.15338,
  title  = {A Spigot-Algorithm for Square-Roots: Explained and Extended},
  author = {Mayer Goldberg},
  journal= {arXiv preprint arXiv:2312.15338},
  year   = {2023}
}
R2 v1 2026-06-28T14:00:49.866Z