In this study we tested the effects of schema-based instruction (SBI) strategies on 3 rd grade students' mathematics skills. We compared SBI to general strategy instruction (GSI) when teaching multi-step word problems to students in mixedabilities general education classrooms. SBI strategies were used to instruct students in an attempt to increase understanding of mathematical word problems, assist with planning a strategy, solving, and checking problems. We assessed the overall effectiveness of SBI on students' procedural accuracy and computational accuracy with mixed computation word problems. Students' attitudes toward problem solving were compared before and after the use of SBI. ANCOVA was used to analyse pre/post-test data on overall problem-solving, procedural and computational fluency, and attitudes toward mathematics. The results indicated that the treatment group consistently outperformed the comparison group on all three achievement assessments by a statistically significant margin, on measures of overall problem-solving ability, procedural fluency, and computational fluency, but not on attitudes towards mathematics. The intervention was shown to be beneficial for enhancing student learning of math across a number of academic constructs.