Peningkatan kemampuan pemahaman konsep matematika materi pecahan dengan model demonstrasi berbantuan media puzzle

Students have difficulty when solving questions about understanding mathematical concepts. Students have difficulty solving questions that require more than one step of completion. So that students' understanding of mathematical concepts is still below the KKM value. This study aims to improve teacher teaching skills, student learning activities and the results of understanding the ability of the concept with the application of demonstration models assisted by puzzles on mathematics subjects in addition and subtraction fractions. This class action research will be conducted in the fifth grade of SDN 3 Mayong with 35 research subjects. This study took place for two cycles, each cycle consisting of four stages, namely planning, implementation, observation, and reflection. The independent variable in this study is the Puzzle-assisted Demonstration model, while the dependent variable is the understanding of students' concepts of addition and subtraction fractions. Data collection techniques using interview, observation, test and documentation techniques. Data analysis used is an analysis of quantitative and qualitative data. The result of this research shows that learning math trough Contextual teaching and learning model using fraction blocks can increase in each cycle. The average score of teacher skill in cycle I is 2,27(pretty good) and it increases 3,21 in cycle II (good). The average score of student learning activity in cycle I is 2,22 (pretty good) and it increases 2,80 in cycle II (good) meanwhile, the result of students’ critical thinking achievement is 54% (less) in pre-cycle. After conducting the research, it obtains 66% (medium) in cycle I and it increases 83% (very high) in cycle II.Based on the result of this research, the researcher concludes that applying the Demonstrationmedia by using Puzzle can improve the teacher skill, student learning activity and the understanding concept ability in math in the materials of fraction in V grade of SDN 3 Mayonglor. The suggestions in this research is that the teacher mush try to improve learning one of which is by applying innovative learning models, using various media and a variety of learning resources. For students to be more passionate and diligent in attending learning, especially in mathematics learning