Within mathematics teaching, ways to help students resolve proportional reasoning problems remains a topical issue. This study sought to investigate how a simple innovative procedure could be introduced to enhance skill acquisition. In two classroom-based experiments, 12-year-old students were asked to solve proportional reasoning mathematics problems, on four occasions, over a two-week period. On the second occasion, students worked either with or without the benefit of worked examples. The examples demonstrated a unitising strategy in the context of solving proportional reasoning missing value problems. Students exposed to the worked examples improved scores on subsequent tests. The worked example instruction was (a) mediated entirely through booklets, (b) effective with both low- and high-SES students and (c) represents a promising approach to teaching within an area that habitually presents many challenges for the general classroom teacher.