Students’ units coordination activity: A cross-sectional analysis

Abstract Students’ ability to coordinate multiple levels of units constitutes a cognitive core in their mathematical development across several domains, including counting, whole number multiplication, integer addition, fractions concepts, and algebraic reasoning. Identifying a progression of students’ units coordination activity would help educators leverage and support student development within and across the three stages of units coordination. This paper contributes to that goal by describing a cross-section of units coordination activity observed during pairs of clinical interviews with 47 grade 6 students. Results include a 36-rank scale of units coordinating activity with accompanying characterizations and descriptors.