In this study, we investigated the effects of a group approach versus a non-group approach on the mathematics performance of learners. A group approach refers to an arrangement in which learners sit together to discuss and solve mathematics tasks. We studied a convenience sample of low-performing Grade 10 mathematics learners using a quasi-experimental design with a non-equivalent control group. The experimental group was taught using a group approach and the control group using non-group approach instruction. To measure the effects of teaching approaches, we administered a Financial Mathematics Achievement Test (FMAT) before and after the experiment. Using a one-way analysis of covariance (ANCOVA) the study found that learners in a group approach learning environment performed significantly better than learners taught through a non-group teaching mode (p < 0.05). The theory of cognitive load was used to interpret the results. The results suggest that a group approach may be effective when teaching certain mathematics topics in Grade 10 classrooms.