Four studies into characteristics and instructional needs of students with learning disabilities are summarized in this article. These studies are also reviewed in the wider context of mathematics intervention research in special education. These studies generally rely on qualitative methodology, and they are best understood in light of a constructive approach to learning. Two themes bind the four studies reviewed here. The first is what distinguishes students with math difficulties from those that may be considered as having a math disability. The second is the nature of curriculum and how the work described in this special issue departs from structured approaches to interventions that have a long and rich history in special education.