A Digit-Based Algorithm for Computing Square Roots of Perfect Squares
DOI:
https://doi.org/10.5433/1679-0375.2026.v47.54706Keywords:
quare root algorithms, perfect squares, digit patterns, arithmetic progression, asymptotic complexityAbstract
This paper presents a new method for computing square roots of perfect squares, originally devised by two students from Basic Education during their mathematics studies. Motivated by numerical patterns observed in the decimal representation of perfect squares, the method combines classical properties of unit digits with a novel block-based structure derived from arithmetic progressions. These patterns allow the construction of an explicit algorithm that recovers the square root of a perfect square using only elementary operations. The work provides a rigorous mathematical formalization of the method, including proofs of correctness, an analysis of its asymptotic behavior, and a discussion of its computational complexity. Beyond its theoretical interest, the proposed approach highlights the mathematical creativity of young students and illustrates how elementary observations can lead to meaningful mathematical structures, reinforcing connections between school mathematics, undergraduate research, and outreach activities.
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References
Brown, P. R. (2021). Detecting square numbers. Quaestiones Mathematicae, 44(2), 163–185. https://doi.org/10.2989/16073606.2019.1678530
Knuth, D. E. (1997). The art of computer programming (Vol. 2, 3rd ed.): Seminumerical algorithms. Addison-Wesley.
Niven, I., Zuckerman, H. S., & Montgomery, H. L. (1991). An introduction to the theory of numbers (5th ed.). John Wiley & Sons.
Norris, F. R. (1974). An algorithm for determining perfect squares. ACM SIGCSE Bulletin, 6(3), 8–12. https://doi.org/10.1145/988881.988882
Pareth, S. (2026). Exact constructive digit-by-digit algorithms for integer e-th root extraction (arXiv:2601.02703) [Preprint]. arXiv. https://arxiv.org/pdf/2601.02703
Pólya, G. (1945). How to solve it: A new aspect of mathematical method. Princeton University Press.
Rolfe, T. J. (1987). On a fast integer square root algorithm. ACM SIGNUM Newsletter, 22(4), 6–11. https://doi.org/10.1145/37523.37525
Rudin, W. (1976). Principles of mathematical analysis (3rd ed.). McGraw-Hill.
Savarimuthu, S. R., Muthuraji, K. C., & Eswaran, P. M. (2023). Square root for perfect square numbers using Vedic mathematics. AIP Advances, 13(2), Article 020047. https://doi.org/10.1063/5.0164287
Sipser, M. (2012). Introduction to the theory of computation (3rd ed.). Cengage Learning.
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Copyright (c) 2026 João Alexandre Zambaldi Garcia, Felipe Kenji Iokota, Paulo Liboni, Luís Rafael Carvalho Moreira, Pablo Marcelo Arboleya Nogueira, Eduardo Henrique de Santana, Fabrício Ventura da Silva

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