Sian and Chris act very differently in these two extracts: Sian does not question the teacher any further, but we might suggest that perhaps this is because she does not need to. However, Black tells us that in fact she did not understand, and had to seek help from Black herself. The teacher also acts differently in the two exchanges gives Chris "clues" in a way that could be seen as scaffolding, but simply tells Sian a partially complete method which contains a clue (division by 5 versus division by 2) but is not explicit enough for Sian to understand, although her "oh right" signals to the teacher that she has. Black speculates on the longer-term outcome of her role in other exchanges: