Globally education authorities are placing increasing emphasis on the development of literacy and numeracy in primary schools. This paper reports on research designed to assist teachers to improve the numeracy of their students by making the use of mathematics games a more focused aspect of the teaching and learning experience in mathematics. Classroom experience and anecdotal evidence suggest that games are often used without really focussing on the mathematics involved in playing the game,and are justified simply on the basis of children having ‘fun’. In this paper we report on the use of one game, Numero and how teachers made use of the game and the impact on the children’s learning when using the game.