The authors examined the effectiveness of strategy instruction taught by general educators in mixed-ability classrooms. Specifically, the authors compared the mathematical word problem-solving performance and computational skills of students who received schema-based instruction (SBI) with students who received general strategy instruction (GSI). Participants were 60 3rd-grade student participants randomly assigned to treatment conditions. Teachers pretested and posttested participants with mathematical problem-solving and computation tests, repeatedly measuring their progress on word problem solving across the 18-week intervention. Both SBI and GSI conditions improved word problem-solving and computation skills. Further, results show a significant difference between groups on the word problem-solving progress measure at Time 1, favoring the SBI group. However, this differential effect did not persist over time. The authors discuss implications for future research and practice. (Contains 3 figures and 3 tables.)