An A-B single-case design assessed at-risk students' responsiveness to mathematics interventions. Four culturally and linguistically diverse second-grade students were given a Tier 2 standard protocol mathematics intervention that included number sense instruction, modeling procedures, guided math drill and practice of addition and subtraction facts, corrective feedback, Touch Math instruction, and reinforcement for on-task behavior. Weekly AIMSweb math computation probes were used to assess responsiveness to intervention. Nonresponders were provided with a second phase of Tier 2 intervention that included an extra day of intervention support. The Tier 2 multicomponent mathematics intervention differentiated responders from nonresponders and showed increases in fact computation. Data also suggest that modifications to Tier 2 support may be an important step to further differentiate responders from nonresponders prior to consideration of Tier 3. Implications of the findings will be discussed as they relate to applied practices in schools.