The purpose of this research was to find out whether there was an effect of applying the Jigsaw cooperative learning model to the ability to solve math problems on the subject of Statistics for fourth-grade students at Elementary Public School Mojosari 01 Jember? To achieve this research purpose, a quasi-experimental study was carried out using the non-equivalent control group design pattern. The research subjects were taken from 40 students of class Iva and IVb at Grade IV of Elementary Public School Mojosari 01 Jember Regency using a purposive sampling technique. Test data collection techniques are used to collect the required data. After the data is collected completely, then the data is analyzed using t-test techniques and relative effectiveness tests. The results of data analysis can be concluded that there is an effect of applying the Jigsaw cooperative learning model to the ability to solve mathematical problems on the subject of Statistics in class IV students at Grade IV of Elementary Public School Mojosari 01 Jember. Furthermore, based on the results of the relative effectiveness test, the relative effectiveness level of the Jigsaw learning model is 33.3% for the ability to solve mathematical problems on the subject of statistics in fourth-grade students at Grade IV of Elementary Public School Mojosari 01 Jember.