The purpose of this study is to describe the proportional reasoning of fourth-grade students in solving missing value problems in multiplication and division. Using a descriptive qualitative design, the study involved 26 fourth-grade students at SDN Lowokwaru 5 Malang City. Data collection methods included tests, observations, interviews, and documentation. The findings reveal that students demonstrate better proportional reasoning in multiplication contexts through scaling strategies, where they can identify multiplicative factors and apply them consistently. However, students encounter greater difficulties in division contexts, particularly in unit rate reasoning. Most students still rely on additive strategies when solving division problems, indicating they remain at the pre-proportional stage. The analysis shows five reasoning stages: understanding the situation and identifying quantities, forming ratio representations, identifying multiplicative structures, applying solution strategies, and evaluating ratio equivalence. Students who successfully form structured representations (tables, fractions, arrows) tend to reach multiplicative reasoning, while those using unstructured representations remain trapped in additive patterns. This research provides important insights for developing teaching strategies that strengthen conceptual understanding of proportional relationships at the elementary school level.