Currently, the teaching of retake GCSE mathematics in further education is predominantly teacher-centred and transmission-oriented. This paper argues that this approach is ineffective for students' learning and for their attitudes towards learning and that a student-centred, collaborative approach to learning, where discussion and reflection are central, can prove more effective in developing students' understanding of and attitudes towards mathematics. A teaching resource encouraging the discussion-based learning of algebra was developed and introduced to teachers of retake GCSE classes from 44 further education colleges. Outcomes relating to students' learning and attitudes towards learning were evaluated. The results indicate that learning increased with both the number of activities used and the degree to which the teaching was reported (by students) as student-centred. Learning gains were modest, reflecting the difficulty of algebraic concepts for these students. Students' confidence, motivation and anxiety remained largely unchanged, in contrast to a control group, where the more transmission-based approaches were associated with a small decline in these aspects. (Contains 4 figures and 4 tables.)