This study aims to determine: (1) the effectiveness of the problem-based math module of zakat to improve students’ mathematical problem solving skills in MA. The private Darul Mursyidi Sialogo Islamic Boarding School; (2) to determine the improvement of students’ mathematical problem solving abilities by using the problem-based math module of zakat. This research is a development research using 4-D development developed by Thiagarajan. The stages are define (define), design (design), develop (development) and disseminate (spread). Research on the development of the problembased math module of zakat at the disseminate stage was carried out in a limited manner in schools which were the research subjects. The subjects in this study were students of class XI MA. Private Darul Mursyidi Sialogo Islamic Boarding School. From the results of the development test: (1) the problem-based zakat math module meets the validity criteria with a valid predicate, (2) the practical problem-based zakat math module based on the revision of the expert team and the results of interviews, and (3) the problem-based zakat math module is effectively used based on the results of the observation of the ideal time percentage achievement, the results of the test of mathematical problem solving abilities meet classical completeness, namely 80% of the test subjects, and (4) an increase in students’ mathematical problem solving abilities using modules from test I to trial II and fulfill classical completeness.
Keywords: Zakat; mathematics module; problem solving