Math Habits, Routines, and Actions is a classroom observation tool intended for math education practitioners or researchers to assess the quality of math instruction. The tool assesses students’ habits of mind and habits of interaction and teachers’ routines and actions. Data generated by the tool allows the user to analyze relationships between teachers’ routines and actions and students’ habits of mind and interaction. The data offer practitioners information to inform formative assessment of classroom practice and researchers information on the quality of instruction.