Research suggests that there are two major reasons for the low numbers taking Higher Level mathematics in Ireland: namely, ineffective teaching and a subsequent lack of student interest in the subject. Traditional styles of teaching make it difficult for students to take an interest in a confusing topic in which they can see no immediate relevance. This is particularly true regarding the topic of algebra and its teaching in school. This paper describes a pedagogical framework designed by the authors for the effective teaching of algebra at lower secondary level in Irish schools that engages students, and promotes interest in the domain. This framework has provided the basis for the design and development of a teaching intervention that has been piloted in Irish schools. In this paper the authors focus on the design of the pedagogical framework and its use to develop classroom materials for a school-based intervention.