Spice up your warm-up time and add a low-stakes formative assessment strategy to your repertoire! Get students moving and talking about math (and possibly arguing about math) by using this "4-Corners" strategy! Using 4 different sets of similar problems included here, students FIRST work individually on a brief set of problems. Students may not realize that there are 4 different versions of the problems floating around the classroom just yet! Then, after a few minutes of independent work, send s