Some students are unsuccessful in algebra. The purpose of this quantitative study was to examine the effects of a mathematics intervention class on students' algebraic skills through a pretest-posttest experimental design. This study addressed a missing piece in current literature on previewing, a teaching strategy typically used in language arts. Math intervention was a supplemental math class that previewed algebraic concepts based on the scaffolding theory. Ninety at-risk algebra students were in the study, evenly divided into a control group and an experimental group (i. e., the math intervention). An independent samples t-test was conducted to determine whether the amount of gain was different between these two groups of students. This analysis yielded a statistically significant difference, t(80) = 9.276, p = .0001, indicating the efficacy of the intervention. This study contributes to social change in that the findings demonstrate for school personnel how to proactively prevent at-risk algebra students from getting "left-behind" and help them succeed in algebra. Without math education reform, students may not acquire the math skills required for employment in well-paying jobs in today's economy. What is the sample of this study?