ABSTRACT
This study aimed to develop Predict-Observe-Explain worksheets on elementary school mathematics subjects in plane material. The approach in this study used a mixed method with Research and Development (R&D) methodology. Data collection instruments were validation questionnaire instruments, teacher response questionnaire instruments, and concept comprehension test instruments, which have been calculated through validity and reliability tests. Data analysis techniques used the data analysis of validity, data analysis of practicality, and data analysis of product effectiveness of a difference test of mathematical concepts comprehension through paired sample t-test. The results showed that the validation of Predict-Observe-Explain worksheets on elementary school mathematics subjects amounted to 81.9% and had very good criteria. Practical results from the teacher response amounted to 83.1% and had very good practicality criteria. The results of the effectiveness test contained differences in mathematical concepts comprehension before and after the use of Predict-Observe-Explain worksheets were 50.73 and 74.41. The conclusion of this study was that the development of Predict-Observe-Explain worksheets on elementary school mathematics subjects of was valid and practical, and could improve the students’ mathematical concept comprehension.
