This formative study of a multiplicative reasoning (MR) intervention explored the intervention's potential for improving the ability of third-grade struggling students' ability to reason with multiplicative concepts and procedures. The feasibility of the study was examined in a school setting before a randomized control trial was conducted. Students who scored between the 10th and 35th percentile on a district-administered math screening test received the MR intervention from their teachers. We developed intervention units to build a conceptual foundation in a student-centered approach to Tier 2 instruction that included opportunities for students to engage in critical thinking as they generalized big ideas, participated in classroom discourse, and modeled multiplicative relationships with multiple representations. Preliminary data demonstrate the potential of the intervention to promote students' MR skills. Instructional implications are discussed in terms of opportunities for these students to engage in grade-level mathematics content.