This paper reports on a case study aiming to deepen our understanding of low achieving students' learning of algebra, in particular when they work with pattern problems. We observed one low achieving student, May, who participated and worked in three different heterogeneous settings. Data were analysed from a multimod-al perspective on key and regulating activities in the groups. The analysis revealed that May's contribution varied, depending on the composition of the groups, and that her contributions were influenced by regulating activities by peers and access to physical artefacts. The findings show that a low achieving student is able to generalise beyond her arithmetic knowledge, but the environment in a heterogeneous group did not offer her the space to do so.