The present review builds on earlier research that evaluated the curricular features of core math programs to improve the performances of students with or at risk for mathematics difficulties. In this review, three elementary math programs, at Grades 2 and 4, were evaluated for the presence of eight instructional principles. Math intervention studies have empirically validated these principles for promoting math proficiency of students struggling with mathematics. Data were collected via a researcher-developed scoring rubric. Findings indicate that adherence to the instructional principles varied markedly within and across programs. In addition, the results indicated that the current textbooks contain a general lack of explicit instruction and provide too few practice opportunities to teach material to mastery. Implications for future curricular reviews and enhancing core math instruction are discussed. (Contains 3 tables.)