Grationality, With a Spoon
Abstract
I introduced grationality at a 2025 sectional meeting of the Mathematical Association of America to install a handle on a concept akin to rationality of numbers, but in a geometric context. More specifically, we define a nice n-gon to be a regular n-gon with side lengths that are natural numbers; then a number n is grational if and only if there exists a nice n-gon such that its area equals the sum of areas of n congruent nice n-gons. In this paper I offer 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.
Fields of Study & Subjects
Mathematics and Applications
History and Theory of Mathematics
Art
Technology
and Culture
Publication details
- Journal / source
- Journal of Humanistic Mathematics
- Volume
- 16
- Issue
- 2
- Pages
- 51–79
- Publication date
- 1 July 2026
- Language
- EN