Development of Mathematics Learning Tools Based on STEM-PJBL: Validity and Practicality

Project-based learning tools need to be developed to improve mathematical problem-solving skills. This research aims to (1) produce project-based learning tools with a STEM approach that are valid and practice the data handling materials, and (2) determine the effectiveness of STEM-PjBL tools in improving students' mathematical problem-solving abilities. The research method used was development research which consists of Preliminary Research, Prototyping, and Assessment phases with the research subjects of SMPN 6 Denpasar students. Data was collected by tests, observations, and documentation. The validation results of the learning tools show that the Student Book meets the valid criteria with an average validity score of 3.47. The teacher's manual meets the very valid criteria with an average validity score of 3.82, and the lesson plan meets the very valid criteria with an average validity score of 3.61. The results of the field test showed that the teacher's book met the practical criteria with an average score of 3.11 in field test II. The student's book met the practical criteria with an average score of 3.01 in field test II. The lesson plan met the practical criteria with an average score of 3.25 in field test II. The implementation of STEM-PjBL tools improves the student?s mathematical problem-solving skill by 68,35 in the field test I and by 71,13 in the field test II. The conclusions of this study are the learning tools developed in this study are categorized as valid and practical and are able to improve students' mathematical problem-solving abilities.