A Deaf-Didactic Case Analysis Using the Example of a "Kangaroo Math" Task

Mathematical word problems are regarded in mathematics education as a central instructional and diagnostic tool, as they require not only computational skills but, in particular, competencies in mathematical modelling, situation analysis, and representational transformation. For deaf students whose first language is German Sign Language (DGS), however, word problems pose a particular challenge, as they are typically based on linguistically linear and auditive-oriented modes of representation.

Within an empirical study on Deaf Didactics in mathematics education (Staudt, 2024), it was repeatedly observed that deaf learners encounter specific comprehension difficulties when working on mathematical word problems. These difficulties cannot primarily be attributed to a lack of mathematical competence. Rather, disruptions occur within the process of mathematical modelling itself—specifically in the construction of a situation model, the translation of linguistic information into mathematical relations, and the coordination of different representational levels.

These observations were systematically analysed by the Deaf Didactics research team at the SignGes Center for Sign Language and Gesture Studies at RWTH Aachen University under the direction of Dr. Klaudia Grote. On this basis, a conventional mathematical word problem originally designed for hearing students was deaf-didactically adapted. The aim was to demonstrate, in an exemplary manner, how mathematical word problems can be designed to take into account the visual, linguistic, and cognitive prerequisites of deaf learners and thereby provide access to mathematical thinking.

In an empirical pilot study, a so-called Kangaroo problem was presented to one hearing and one deaf child, both aged ten years. This type of task typically requires logical reasoning, systematic elimination of possibilities, and flexible handling of relational information. While the hearing child was able to solve the task quickly and correctly, the deaf child experienced considerable difficulties in reading, structuring, and interpreting the problem statement.