Detailing is a linguistic tool for mathematical argumentation in which given mathematical information is operationalized through one's warrants to support a claim. Recent literature suggests that students' detailing is related to their early algebraization. This study examined 168 elementary students' use of detailing in two mathematical argumentative tasks in relation to their enacted scheme of multiplicative unit coordination. A convergent mixed methods approach was used to analyze students' argumentative writing qualitatively, and merge these findings with quantitative indicators for students' multiplicative reasoning. Results suggest a statistically significant relationship between students' detailing and their multiplicative unit coordination. [For the complete proceedings, see ED583608.]