The purposes of this study were twofold. The first was to test the efficacy of two versions of the "Super Solvers" (SS) intervention for fourth- and fifth-grade students at-risk for mathematics learning disabilities (MLD). The second was to test the value of adding an error analysis component to the SS intervention. Students were randomly assigned to a business-as-usual control condition or to receive one of two versions of the SS intervention: (a) "Super Solvers" or (b) "Super Solvers" plus conceptual and strategic error analysis of fraction calculations. Both versions of SS comprised 39 lessons delivered to student dyads three times per week over 13 weeks. Lessons focused on developing students' conceptual and procedural knowledge of fraction magnitudes and calculation skills. At posttest, students who received either SS intervention significantly outperformed those in the control condition on measures of fraction magnitude knowledge (ESs = 1.22 to 1.47) and calculations (ES = 1.72) but on a far-transfer of general fraction knowledge (ES = 0.05). Results did not differ between the two interventions. These results provide strong evidence for the efficacy of SS for improving fraction performance of fourth- and fifth-grade students at-risk for MLD.