The teaching material contains reflections on three mathematical concepts:

The concept of Triangle is used to introduce the practice of language comparison in a conceptually simple case: Tri-ángulo (Spanisch for “three-angle”), Drei-eck (German for “three-vertex”), Tre-kant (Danish for “three-side”); each refers to different components of the triangle. By discussing differences, students become aware that unpacking words can be mathematically interesting.

Area and perimeter provide the second example and focuses on conceptually challenging students to clearly distinguish between them. Omtrek (Netherlands for “around-track”) speaks nicely and is easy to distinguish from Emvadón (Greek “go into something“).

Odd and even is the third example: The different terms for odd and even in multiple languages refer to two models of division: gerade Zahl (German for “levelled-out number”) uses the idea of partitive division, while çift sayılar (Turkish for “couple number”) refers to quotative division.

For the perimeter example, the following 8-minute film provides insights into its implementation in a real classroom.

To quote the material, please use this format:

Uribe, Ángela, Prediger, Susanne, Platen, Yasmin, Ferrari, Eugenia, Lekaus, Silke, Meaney, Tamsin, Revina, Shintia, & Schüler-Meyer, Alexander (2025). Unpacking mathematical concepts in multiple languages: Examples triangle, perimeter and even numbers. Multiple-language-responsive teaching material. German Center for Mathematics Teacher Education. Open Educational Resource under sima.dzlm.de/um/multiple-languages and multilingualmath.nl.