Students’ ability to solve problems is still lacking because they often rely on memorizing concepts. The purpose of this research is to determine the effectiveness of the STAD-type cooperative learning model in helping students solve mathematical problems. This type of research used descriptive quantitative research. This research approach used an experiment with a Quasi experimental design in the form of a pre-test post-test control group design. This research was conducted using a sample of fifth-grade students at Dukuhan Kerten State Elementary School, even semester of the 2022/2023 academic year. This research used a cluster random sampling technique where two experimental and control classes were obtained. Independent Sample T-Test is one type of data analysis test used. STAD and conventional learning models show different levels of effectiveness, as seen from the Sig. (2-tailed) of 0.044 < 0.05 indicated that is rejected. In the Independent sample t-test the mean value of the experimental class also bigger than the mean of the control class, which is 0.4280 > 0.2708. It showed that in improving fifth-grade students’class V mathematics problem solving skills on geometric material, the STAD learning model is more effective to use.