The basis of the problem faced is the mathematical problem solving ability (KPMM) of MTs PP students. Nurul Islam Kampung Baru class VIII.1 is low. Therefore, research was carried out which intended to fixed the learning process and build KPMM of MTs PP students. Nurul Islam Kampung Baru class VIII.1 to be more improved by application a problem-based learning (PBL) model on the topic of flat-si…