Dialogue and reasoning are central to mathematics. Despite a substantial body of research illustrating the benefit of talk in the classroom, an educational debate remains in schools about how much time and empowerment should be given to children to talk in lessons. For many teachers, particularly post-pandemic, there is a professional concern about the quality of children's communication skills. An example of this is that many children appear to have difficulty in engaging in productive mathematical dialogue, and struggle to articulate their reasoning strategies. This paper explores children's class-based experiences of using talk cue cards as resources intended to support dialogue and hence mathematical reasoning. A case study approach was used to explore the experiences of key stage 2 children. The study showed that talk cue cards could break down some barriers to effective communication and so enhance children's quality of mathematical reasoning, whilst supporting engagement in metatalk about reasoning. Potential implications for educators are explored in terms of both classroom and mathematical practices such as: co-constructing agreed hallmarks of high-quality talk; teacher and peer modelling; and allotting time for the exploration of the talk cue cards.