Gareth was Principal of Coleg Normal Bangor (1994-96), thereafter Pro Vice-Chancellor (1996-2005) and Professor of Education (2000-2005) at Bangor University and then Emeritus Professor at the university. He specialises in mathematics education with an emphasis on bilingual education.

Gareth graduated in Mathematics at Jesus College, Oxford, and took his doctorate at the University of Nottingham, where he applied Quantum Theory to study the mathematics of aromatic molecules. Awarded a University of Wales Fellowship at the Department of Applied Mathematics at UCNW he then held posts at Glamorgan Polytechnic (currently University of South Wales) and the Open University. He subsequently developed an interest in mathematics education and took an MEd at Cardiff University before being appointed as a Mathematics Adviser for Gwynedd County Council and was then appointed to Coleg Normal Bangor.

Gareth has contributed extensively to the popularisation of mathematics in articles, books and on the media, including social media. In 2010 he was awarded the Science and Technology Medal by the National Eisteddfod for his contributions to mathematics. At the Eisteddfod in Wrexham in 2011 he was accepted as a member of the Assembly of Bards, acquiring ‘Gareth Ffowc’ as his bardic name. He was elected Fellow of the Learned Society of Wales in 2016 and was made an Honorary Fellow of Coleg Cymraeg Cenedlaethol in 2018. In recognition of his public distinction he was awarded an Honorary Doctor of Science in 2023 by Bangor University.