Teaching and learning algebra has undergone a critical transformation in the US over the last two decades. Recognizing that historical paths to algebra have been largely unsuccessful in terms of students’ achievement in algebra, mathematics education scholars have increasingly advocated that algebra be re-conceptualized in school mathematics as a longitudinal, grades K-12 strand of thinking. In particular, scholars advocate that students have long-term, sustained algebra experiences in school mathematics, *beginning in the elementary grades*, that build their natural, informal intuitions about structure and relationships into formalized ways of mathematical thinking.

Along these lines, early algebra research has provided us with important evidence regarding children’s ability to think algebraically**. **However, the majority of this work might not be viewed as sufficiently comprehensive in its approach in that the research has often focused on specific early algebraic domains to the exclusion of others (e.g., functional thinking vs. generalized arithmetic). Moreover, such research has not yet systematically addressed how the development of children’s algebraic thinking impacts their understanding of core algebraic concepts in comparison to students who receive more traditional arithmetic-based instruction. Indeed, a fundamental assumption of early algebra education is that it will increase children’s understanding of algebraic concepts and, ultimately, improve their success in the study of more advanced mathematics—particularly algebra—in secondary grades. To date, however, this premise is largely untested. In a series of three related projects (described below), we are seeking to address this premise.

In our first project, *Developing Algebra-Ready Students for Middle School: Exploring the Impact of Early Algebra*, we constructed an Early Algebra Learning Progression [EALP] consisting of a curricular framework and progression developed by coordinating research, curricular, and mathematical perspectives; a Grades 3-5 instructional sequence based on the framework and progression; associated assessments; and levels of sophistication describing strategies observed in children’s mathematical work. We also conducted a preliminary study to examine the impact of our EALP’s instructional intervention as measured by our assessments.

In our second project, *The Impact of Early Algebra on Students’ Algebra-Readiness*, we utilized the tools developed in the first project to conduct a small scale, quasi-experimental, longitudinal study of our EALP’s instructional intervention in Grades 3-5. In particular, we compared the performance of students who received the early algebra intervention to students who received more traditional elementary grades instruction.

In our third project, *The Impact of a Teacher-Led Early Algebra Intervention on Children’s Algebra-Readiness for Middle School*, we are scaling up our work in the second project to a much larger number of schools and classrooms and are studying the effectiveness of our EALP’s instructional intervention when implemented by regular classroom teachers.