This paper reports on a small-scale intervention that explored perseverance in mathematical reasoning in children aged 10–11 in an English primary school. The intervention facilitated children's provisional use of representations during mathematical reasoning activities. The findings suggest improved perseverance because of the effect the intervention seemed to have on the bidirectional interplay between affect and cognition. This initially created affectively enabling conditions that impacted on cognition and then created cognitively enabling conditions that impacted on affect. A tentative framework describing this interaction is proposed.