Abstract
High school mathematics can have a direct impact on the academic, health, and financial outcomes of students. To understand how to better support students experiencing mathematics difficulty (MD) in Grades 9, 10, 11, and 12 (i.e., high school), we conducted a synthesis of 21 studies in which author teams investigated the efficacy of a mathematics intervention across a total sample of 197 students. Overall, 15 studies demonstrated positive outcomes, with four studies demonstrating no effects and two studies demonstrating mixed results. We identified several instructional strategies used across multiple studies: explicit instruction, use of technology, focus on vocabulary, use of representations, and word-problem instruction. In most studies, researchers used single case designs, and most of the mathematics content focused on early algebraic standards. As such, there is a need for more mathematics intervention research at the high school level.