Grationality, With a Spoon
Abstract
The introduction of Grationality at a 2025 sectional meeting of the Mathematical Association of America installed a handle on a concept akin to rationality of numbers, but in a geometric context. A nice -gon was defined to be a regular -gon with side lengths that are natural numbers, and a number was defined to be grational if and only if there exists a nice -gon such that its area equals the sum of areas of congruent nice -gons. This paper shows several examples of grational and non-grational numbers, followed by theorems about how the grationality of a number relates to its divisibility. Proofs of these theorems do not use high-powered tools, but rely on geometric constructions, proportional reasoning, tiling, dissection, the Carpets Theorem, and proof by descent. In keeping with this simplicity, a.k.a. "doing math with a spoon," images are heavily leveraged. The benefits of choosing simplistic tools are discussed.
Cite
@article{arxiv.2508.08267,
title = {Grationality, With a Spoon},
author = {L. Jeneva Clark},
journal= {arXiv preprint arXiv:2508.08267},
year = {2025}
}
Comments
21 pages, 40 figures