<![CDATA[The expansion of social media has opened possibilities for mathematics education through flexible and interactive learning environments. Nevertheless, its use remains insufficiently explored to develop pre-service mathematics teachers’ mathematical creative thinking in Linear Algebra, where abstract vector concepts require opportunities to generate, vary, and justify ideas. This study aimed to develop Instagram-based interactive microlearning for vector material and investigate its validity, practicality, and effectiveness in fostering mathematical creative thinking in terms of fluency, flexibility, and originality. Using a Research and Development approach guided by the ADDIE model, the study comprised Analysis, Design, Development, Implementation, and Evaluation stages. Product validity was examined by three experts, whereas practicality was assessed through a small-group trial with 10 pre-service mathematics teachers and an extended field trial with 20 participants. Effectiveness was evaluated using a quasi-experimental non-equivalent control-group pretest–posttest design involving 40 pre-service mathematics teachers, with 20 assigned to each group. Data were collected through expert validation sheets, student response questionnaires, and mathematical creative thinking tests. The developed media demonstrated high validity based on media (3.50), subject matter (3.58), and learning (3.83) expert assessments, and very high practicality in both the small-group (3.59) and field (3.55) trials. The experimental group increased from 6.28 to 8.58, compared with 5.88 to 7.93 for the control group. The N-Gain was 0.59 versus 0.47, with a significant difference, t . ANCOVA confirmed a significant group effect, , partial η² = .364. These findings establish Instagram-based interactive microlearning as a promising medium for strengthening mathematical creative thinking in Linear Algebra.]]>
