This study focuses on pre-school children’s talk while they are solving subtracting problems with peers. In this study, a socio-cultural perspective is used. In a socio-cultural perspective, learning and knowing are situated at the intersection of individual and collective action, and learning is seen as an emergent property of involvement in cultural practices. To understand children’s interaction and how they mediate their mathematical knowledge, important concepts used in this study are also collected from Bruner’s “Theory of representation”. When the quality of talk between pre-school children could be related to disputational or cumulative talk the children do not exchange ideas and thereby do not develop their reasoning ability as much as they do when they are engaged in exploratory talk. Disputational talk and cumulative talk draw children’s attention to procedural fluency or the concept of numbers. Depending on what representation forms are used by the children doing the explaining, the other children in the group are exposed to either the concept of numbers or procedural fluency.