Many educators focus on the cognitive and/or cultural/contextual deficits that students bring to learning tasks, which are oftentimes used to explain poor academic performance. Metacognition that can be taught and learned for improving learning performance is regarded as an alternative. The purpose of this year-long collaborative action research is to describe how a culturally relevant metacognitive formative assessment strategy called TALE (Take Another Look Everyone) worked in a rural 5th grade mathematics classroom (N = 16). A variety of data was collected, recorded, co-transcribed, co-reflected, and systematically co-analyzed. Major findings were that students' formative test scores substantially increased and two cases of students with different backgrounds, including Native American culture, and academic levels, demonstrated different ways of improving mathematics proficiency. This paper concluded that students learned better when given an opportunity to metacognitively think about mistakes in a highly respectful classroom.