This study uses a Blended Learning model that combines two face-to-face
and online lessons. This Classroom Action Research (CAR) was carried out in
class IV to improve students' understanding of mathematics lessons on flat
shapes through the Blended Learning model assisted by teaching aids and video
media. In this study, the total number of fourth grade students was 22 students,
consisting of 12 male students and 10 female students. Classroom Action
Research that will be carried out is through 2 cycles consisting of cycle I and
cycle II, where each cycle consists of 2 meetings. The implementation of each
cycle includes planning, implementation, observation, and reflection. Data
collection in this study was taken from student evaluation sheets and teacher and
student activity observation sheets. This increase in understanding is evidenced
by the acquisition of an average score in the first cycle, which is 69.63 with
sufficient criteria and the acquisition of an average score in the second cycle,
which is 80.31 with very good criteria. Classroom Action Research that has been
carried out in class IV, it can be concluded that the understanding of students in
mathematics lessons on flat shapes can be increased through Blended Learning.