Algebra I is considered a gateway course for advanced math. Consequently, there has been a trend toward enrolling students in Algebra I earlier in the middle grades in order to increase opportunities for students to take more advanced math courses in high school. The challenge for educators lies in determining which students are ready to take Algebra I in middle school and which students need more time to develop foundational knowledge and skills before taking Algebra I. To inform strategies that address this challenge, educators from the Missouri Department of Elementary and Secondary Education partnered with Regional Educational Laboratory Central to investigate the specific foundational knowledge and skills that are associated with achievement in Algebra I. This study examined whether student knowledge in five domains of math assessed in grade 7 was associated with Algebra I achievement. The study found that students' scores in all five of the grade 7 domains were related to Algebra I achievement, but their performance in the expressions, equations, and inequalities domain was most strongly related. The number sense and operations domain was more strongly associated with Algebra I achievement for English learner students than it was for students without this designation. No clear differences in these associations were found between students who were receiving special education services and those who were not.
