Reasoning-and-proving in algebra: The case of two reform-oriented U.S. textbooks

•Reasoning-and-proving in exposition and tasks in two reform algebra texts examined.•Statistically significant differences between texts in tasks and exposition sentences.•Statistically different treatment across algebra subtopics in each text.•Few patterns or conjectures were tied to the development of arguments.•Technology not well represented across categories in either text. This research study examined students’ opportunities to engage in reasoning-and-proving (RP) within exposition and task components of two U.S. reform-oriented secondary algebra textbooks. There were statistically significant differences between the two textbooks in terms of the percentage of tasks coded as RP and statistically significant differences in the percentages of tasks devoted to RP across different algebra topic areas within each textbook. Differences also appeared in the role of technology in RP within both textbooks. While this study is focused on two U.S. algebra textbooks, broader recommendations will be made on textbook design with regard to RP. Moreover, the framework presented in this study provides researchers and teachers with tools to examine RP in textbooks and enacted classroom lessons.