<![CDATA[Written mathematical communication was important to investigate because correct answers did not reveal how students identified information, represented ideas, used symbols, and organized solution steps when solving plane-geometry problems. This qualitative study aimed to describe the characteristics of students’ written mathematical communication in solving a rectangle problem based on gender and response completeness. It involved four seventh-grade students from an Islamic junior secondary school in Malang, Indonesia: one male and one female student with complete responses, and one male and one female student with incomplete responses. Data were collected through a written mathematical communication test and analyzed through data reduction, data display, and conclusion drawing. Data credibility was strengthened through member checking. The findings showed that mathematical expressions were the main communication form for all students. The male student with a complete response used symbols and equations without visual representation, whereas the female student with a complete response integrated a labeled sketch, mathematical expressions, and written explanations coherently. Both students with incomplete responses relied on algebraic procedures, omitted sketches and initial information, and did not provide concluding statements. However, the female student organized the procedure more systematically than the male student. These findings extended the literature on gender-based written mathematical communication by showing that communication tendencies were not fixed but were associated with response completeness, representational choices, and procedural organization.]]>
