The study investigated the experience of students enrolled in the same first-year mathematics subject at an Australian university, whose learning environment had naturally occurring differences. One group was very much smaller than the other, and taught by a smaller team, so that organisational coordination of teaching was simpler for the small group, and access to staff support easier. In addition, the small group had additional formative teaching material designed to clarify the requirements of subject assessments, and to foster students’ getting started on relevant problem solving There were also initial differences between groups, because the men in the small group contained a high proportion of students repeating the subject after failure. Scales adapted from the SLEI were used to give information about students’ perceptions of their leaning environment. Perceived learning environment factors were linked to achievement, again with some interaction with gender and background. The highest scale scores were for men in the small group, and a comparison of final examination results showed no significant differences associated with class or gender. The conclusion was that the initially disadvantage group of men in the small class had benefitted from their learning environment. Correlations between scale scores and test achievement indicated that women in each group had wider needs from the learning environment than the men in the group.