Abstract
The first part of this paper provides a brief historical account of the development of mathematics teaching and learning through the medium of Welsh. It provides a review of developments which have seen the teaching and learning of mathematics through a native but minority language become an accepted part of the curriculum for a great number of pupils. It goes on to examine the nature of bilingual education currently to be found in Wales by considering two main types of bilingual schools which currently serve Welsh pupils and which have contributed towards a modest but notable minority language revival. It is in this context that current practice relating to Welsh‐medium mathematics is explored and a number of questions concerning current mathematics teaching, learning and assessment practices are raised. While celebrating the success and expansion of bilingual education in Wales, attention is drawn to the need to subject current practice to closer scrutiny. Although the paper focuses on the particular situation to be found in Wales, the issues and questions raised are clearly of interest to those involved with other bilingual educational programmes.