<![CDATA[This research is motivated by the low understanding of the concept of Least Common Multiple (LCM) in elementary school students due to learning that is still teacher-centered and tends to emphasize procedures rather than understanding concepts. The study aims to determine the effect of the Problem Based Learning (PBL) model with a deep learning approach on the understanding of the LCM concept in grade V students of SDN Sidokepung 1. The study used a quantitative approach with a pre-experimental method through a one group pretest-posttest design. The research sample consisted of 34 grade V B students selected using a purposive sampling technique. Data collection was carried out through pretest and posttest essay tests. Data were analyzed using validity tests, reliability tests, Shapiro-Wilk normality tests, and paired sample t-test hypothesis tests assisted by SPSS 25. The results showed that the average pretest score of 54.65 increased to 77.29 in the posttest. The results of the hypothesis test obtained a significance value of 0.000 < 0.05, indicating a significant effect of the application of the PBL model with a deep learning approach on students' understanding of the concept of LCM. The application of problem-based learning combined with meaningful learning can encourage students to be more active, critical, and understand the concept in depth. Thus, the PBL model with a deep learning approach can be used as an alternative mathematics learning to improve elementary school students' conceptual understanding.]]>
