The research reported in this paper explores the applicability and efficacy of a variant of problem-based learning, the Preparation for Future Learning (PFL) approach, to teaching and learning within the context of a cross-curricular, middle school data literacy unit called "Thinking with Data" (TWD). A quasi-experimental design was used to compare pre-to-post-test data literacy gains of seventh grade students participating in the TWD unit with other seventh graders in two middle schools in northeast Ohio. Results show statistically significant differences between the two groups. Taken together with participant comments, the findings suggest that the PFL approach can be effectively implemented across subject areas to support the development of data literacy.