This study aims to analyze the effectiveness of learning materials based on realistic mathematics education approach, as well as improving mathematical problem solving ability and student self-efficacy. Learning materials that developed were lesson plan, student book, student worksheet, mathematical problem solving ability test and self-efficacy questionnaire. This research is a development research by using the development model of Thiagarajan et al. (1974). Learning materials that have met valid criteria according to experts, were tested in class VII of SMP Negeri 17 Medan. The results showed that learning materials based on realistic mathematics education approach met the effective criteria and can improved mathematical problem solving ability and student self-efficacy. Based on the results of the study, it was suggested that mathematics teachers make an effort mathematical learning using learning materials based on realistic mathematics education approach.

• Ansari, B. I. (2012). Komunikasi Matematika Konsep dan Aplikasi. Jakarta: Pena.
• Arisetyawan, A., Suryadi, D., Herman, T., & Rahmat, C. (2014). Study of Ethnomathematics: A Lesson From The Baduy Culture. International Journal of Education and Research, 2(10), 1-8.
• Ayotola, A., & Adedeji. (2009). The relationship between mathematics self-efficacy and achievement in mathematics. World Conference Education Science; Procedia Social and Behavioral Sciences, 1(2009), 953–957. https://doi.org/10.1016/j.sbspro.2009.01.169
• Azwar, Surya, E., & Saragih, S. (2017). Development of Learning Devices Based on Contextual Teaching and Learning Model Based on the Context of Aceh Cultural to Improve Mathematical Representation and Self-efficacy Ability of SMAN 1 Peureulak Students. Journal of Education and Practice, 8(27), 186–195.
• Balım, A. G. (2009). The Effects of Discovery Learning on Students’ Success and Inquiry Learning Skills, Eurasian Journal of Educational Research, (35), 1–20.
• Bandura, A. (1994). Self-efficacy. In V. S. Ramachaudran (Ed.). Encyclopedia of human behavior, (4), 71–81. New York: Academic Press. (Reprinted in H. Friedman (Ed.), Encyclopedia of mental health. San Diego: Academic Press, 1998).
• De Lange. (1996). Using and Appying Mathematics in Education. Dalam Bishop, A. J., et al. International Handbook of Mathematics Education (49-97). London: Kluwer Academic Publisher.
• Fauzan, A., Slettenhaar. D. & Plomp, T. (2002). Traditional Mathematics Education vs. Realistic Mathematics Education: Hoping for Changes. Proceedings of the 3rd International Mathematics Education and Society Conference. Copenhagen: Centre for Research in Learning Mathematics, 1-4.
• Gravemeijer, K. P. E. (1994). Developing Realistic Mathematics Education. Utrecht: Freudenthal Institute.
• Hadi, S. (2005). Pendidikan Matematika Realistik dan Implementasinya. Banjarmasin: Tulip.
• Hadi, S. (2017). Pendidikan Matematika Realistik: Teori, Pengembangan dan Implementasi. Depok: PT Rajagrafindo Persada.
• Hake, R. R. (1999). Analizing Change/Gain Scores. Woodland Hills: Dept. Of Physics, Indiana University.
• Harahap, S. S., Hasratuddin, & Simamora, E. (2018). The Development of Learning Devices Based Realistic Approach for Increasing Problem Solving Mathematics Ability of Student in SMPS Gema Buwana. Journal of International Institute for Science, Technology and Education, 8(1), 14-26. https://doi.org/10.9790/7388-0706071118
• Hasibuan, A. M., Saragih, S., & Amry, Z. (2018). Development of Learning Materials Based on Realistic Mathematics Education to Improve Problem Solving Ability and Student Learning Independence. International Electronic Journal of Mathematics Education, 14(1), 243-252.. https://doi.org/10.29333/iejme/4000
• Hasratuddin. (2018). Mengapa Harus Belajar Matematika?. Medan: Penerbit Perdana Publishing.
• Hudoyo, H. (1988). Mengajar Belajar Matematika. Jakarta: Dirjen Dikti Depdikbud.
• Laurens, T., Batlolona, F. A., Batlolona, J. R., & Leasa, M. (2018). How Does Realistic Mathematics Education (RME) Improve Students’ Mathematics Cognitive Achievement?. EURASIA Journal of Mathematics, Science and Technology Education, 14(2), 569-578. https://doi.org/10.12973/ejmste/76959
• Liu, X., & Koirala, H. (2009). The Effect of Mathematics Self-Efficacy on Mathematics Achievement of High School Students. NERA Conference Proceedings 2009, 30. Retrieved from http://digitalcommons.uconn.edu/nera_2009/30
• Maulydia, S. S., Surya, E., & Syahputra, E. (2017). The Development Of Mathematic Teaching Material Through Realistic Mathematics Education To Increase Mathematical Problem Solving Of Junior High School Students. IJARIIE, 3(2), 2965-2971.
• Motlagh, S. E., Amrai, K., Yazdani, M. J., Abderahim, H. A., & Souri, H. (2011). The Relationship Between Self-efficacy and Academic achievement in high school students. Procedia Social and Behavioral Sciences, (15), 765–768. https://doi.org/10.1016/j.sbspro.2011.03.180
• Nasution, T. K., & Sinaga, B. (2017). Development of Student Worksheet Geometry Based Metacognitive Strategy Through Creative Thinking Ability. IOSR Journal of Research & Method in Education (IOSR-JRME), 7(4), 10-18. https://doi.org/10.9790/7388-0704041018
• NCTM. (2000). Principles and Standards for School Mathematics. Reston, VA: National Council of Teachers of Mathematics (NCTM).
• Nesari, A. J., & Heidari, M. (2014). The Important Role of Lesson Plan on Educational Achievement of Iranian EFL Teachers’ Attitudes. International Journal of Foreign Language Teaching & Research, 3(5), 25-31.
• Nidya, Wulandari, F., & Jailani. (2015). Indonesian Students’ Mathematics Problem Solving Skill in PISA And TIMSS. Proceeding of International Conference On Research, Implementation And Education Of Mathematics and Sciences 2015 (ICRIEMS 2015), Yogyakarta State University, 17-19 May 2015.
• Olayinka, A. R. B. (2016). Effects of Instructional Materials on Secondary Schools Students’ Academic Achievement in Social Studies in Ekiti State, Nigeria. World Journal of Education, 6(1), 32-39. https://doi.org/10.5430/wje.v6n1p32
• Phonapichat, P., Wongwanich, S., & Sujiva, S. (2014). An Analysis of Elementary School Students’ Difficulties in Mathematical Problem Solving. Procedia - Social and Behavioral Sciences, 116(2014), 3169–3174. https://doi.org/10.1016/j.sbspro.2014.01.728
• Pintér, K. (2012). On Teaching Mathematical Problem-Solving and Problem Posing. PhD Thesis, University of Szeged, Szeged.
• Prastini, M., & Retnowati, T. H. (2014). Enhancing Social Ability and Learning Outcomes of Social Sciences through the TGT Cooperative Model at Secang 1 Junior High School. Harmoni Sosial Journal, 1(2).
• Safitri, A., Surya, E., Syahputra, E., & Simbolon, M. (2017). Impact of Indonesian Realistic Mathematics Approach to Students Mathematic Disposition on Chapter Two Composition Function and Invers Fungtion in Grade XI IA-1 SMA Negeri 4 Padangsidimpuan. International Journal of Novel Research in Education and Learning, 4(2), 93-100.
• Sapta, A., Hamid, A. & Syahputra, E. (2018). Assistance of Parents in the Learning at Home. Journal of Physics: Conference Series, 1114(2018), 012020. https://doi.org/10.1088/1742-6596/1114/1/012020
• Saragih, S., & Napitupulu, E. (2015). Developing Student-Centered Learning Model to Improve High Order Mathematical Thinking Ability. International Education Studies, 8(6), 104–112. https://doi.org/10.5539/ies.v8n6p104
• Saragih, S., Napitupulu, E. E., & Fauzi, A. (2017). Developing Learning Model Based on Local Culture and Instrumentfor Mathematical Higher Order Thinking Ability. International Education Studies, 10(6), 104–122. https://doi.org/10.5539/ies.v10n6p114
• Scherer, R., & Beckmann, J. F. (2014). The Acquisition Of Problem Solving Competence: Evidence from 41 Countries that Math and Science Education Matters. Large-scale Assessments in Education, 2(10), 1– 22. https://doi.org/10.1186/s40536-014-0010-7
• Schoenfeld, A. H. (2013). Reflections on Problem Solving Theory and Practice. The Mathematics Enthusiast, 10(1,2), 9–32.
• Skaalvik, E. M., Federici, R. A., & Klassen, R. M. (2015). Mathematics Achievement and Self-efficacy: Relations with Motivation for Mathematics. International Journal of Educational Research, (72), 129–136. https://doi.org/10.1016/j.ijer.2015.06.008
• Sukoco, H., & Mahmudi, A. (2016). Pengaruh Pendekatan Brain-Based Learning terhadap Kemampuan Komunikasi Matematis dan Self-Efficacy siswa SMA. Phytagoras: Jurnal Pendidikan Matematika, 11(1), 11-24.
• Surya, E., Putri, F. A., & Mukhktar. (2017). Improving Mathematical Problem-Solving Ability and Self-Confidence of High School Students Through Contextual Learning Model. Journal on Mathematics Education, 8(1), 85-94.
• Susanti, D. S. (2012). Model Pembelajaran RME (Realistics Mathematic Education) Untuk Meningkatkan Hasil Belajar Matematika Siswa Kelas IV SD Negeri Krapyak 2 Tahun Ajaran 2011/2012. FKIP, PGSD Universitas Sebelas Maret.
• Thiagarajan, S., Semmel, D. S., & Semmel, M. I. (1974). Instructional Development for Training Teachers of Exceptional Children. A Sourcebook Indiana: Indiana University.
• Trianto. (2011). Mendesain Model Pembelajaran Inovatif-Progresif. Konsep Landasan, dan Implementasinya pada Kurikulum Tingkat Satuan Pendidikan (KTSP). Jakarta: Kencana Prenada Media Group.
• Trianto. (2013). Model Pembelajaran Terpadu dalam Teori dan Praktek. Jakarta: Prestasi Pustaka.
• Widjaja, Y., & Heck, A. (2003). How a Realictic Mathematics Education Approach and Microcomputer-Based Laboratory Workedin Lessons on Graphing at an Indonesian Junior High School. Journal of Science and Mathematics Education in Southest Asia, 26(2), 1-51.
• Wulandari, R., Sumardi, & Indah, A. (2014). Pengembangan Perangkat Pembelajaran Berbasis Pembelajaran Matematika Realistik Pokok Bahasan Kubus Dan Balok. Pancaran, 3(1), 131-140.
• Yerizon, Putra, A. A., & Subhan, M. (2018). Mathematics Learning Instructional Development based on Discovery Learning for Students with Intrapersonal and Interpersonal Intelligence (Preliminary Research Stage). International Electronic Journal of Mathematics Education, 13(3), 97-101. https://doi.org/10.12973/iejme/2701
• Zakaria, Effandi, & Muzakkir, S. (2017). The Effect of Realistic Mathematics Education Approach on Students’ Achievement and Attitudes Towards Mathematics. International Scientific Publications and Consulting Services, 2017(1), 32-40. https://doi.org/10.5899/2017/metr-00093
• Zimmerman, B. J. (2000). Self-Efficacy: An Essential Motive to Learn. Contemporary Educational Psychology, (25), 82–91. https://doi.org/10.1006/ceps.1999.1016

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