Cognitive activation is an approach to instruction associated with increased mathematical achievement and engagement. However, researchers have questioned its effectiveness for students with different learner characteristics. A Year 6 class participated in a lesson designed using cognitive activation practices. Interviews with ten case study participants, comprising varying achievement and engagement levels, revealed that practices such as collaborative learning and the use of cognitively demanding tasks evoked positive student responses. The findings highlight the instructional potential of cognitive activation across heterogeneous learner profiles.