ABSTRACT Mathematics is reffered to as a difficult subject by students. The lecture method is still the teacher’s favorite for teaching in class II SDN 1 Plosojenar, this has the impact of students becoming passive, the focus of students is lacking which results in less than optimal learning outcomes and does not reach the minimum criteria completeness, escepially in unit time materials. Through the use of a problem-based learning model, this study seeks to improve students mathematics learning outcomes in the unit time material. This type of research is Classroom Action Research (PTK). The spiral PTK model from Stephen Kemmis and Robin Mc Taggart was chosen in this study using cycles. Each cycle consist of 4 stages namely 1) planning, 2) action, 3) observation, 4) reflection. The research subjects were class II students at SDN 1 Plosojenar Kec. Kaumen, Kab. Ponorogo, totaled 11 students. If the learning outcomes get a value above the KKM≥70 then the learning is said to be successful. The results of the data analysis showed that the learning outcomes of students at the pre-cycle, cycle I, and cycle II stages had increased. At the pre-cycle stage, only 27% of students complete. Then learning outcomes increased in cycle I by 55% of students who completed and increased significantly in cycle II by 82% of students. Through the application of PBL (Problem Based Learning) in learning, students can understand the concept of learning by thinking deeply and learning outcomes increase