Optimizing Slow Learners’ Understanding through Environment-Based Manipulative Media on the Number Operation Topic
), Wildanus Sholihah(2), Hasan Basri(3), Nindian Puspa Dewi(4), Rahmad Rahmad(5), Ainur Rofiq Hafsi(6)
| 
Country:
(1) Department of Mathematics Education, Universitas Madura, Indonesia
(2) Department of Mathematics Education, Universitas Madura, Indonesia
(3) Department of Mathematics Education, Universitas Madura,
(4) Department of Computer Engineering, Universitas Madura, Indonesia
(5) Department of Indonesian Language Education, Universitas Madura, Indonesia
(6) Department of Indonesian Language Education, Universitas Madura, Indonesia
Corresponding Author
Every individual, including students with special needs such as slow learners, has the right to receive equal education. The current study aimed to examine elementary slow learners’ understanding of number operation concepts through the use of manipulative media drawn from their local environment at Pademawu Barat 1 Elementary School, Pamekasan. A qualitative case study design was employed, involving two fifth-grade students identified as slow learners through a diagnostic test, the Colored Progressive Matrices (CPM) psychological assessment, questionnaires, and interviews. Data were collected through formative and summative assessments, classroom observations, and video documentation, then analyzed descriptively and qualitatively, with validation ensured through source triangulation. An individualized learning intervention was conducted using manipulative media such as ice cream sticks and shell boards that were relevant to the students’ coastal environment. The findings revealed that the use of manipulative media combined with structured scaffolding gradually improved students’ understanding of number operations, particularly in addition, subtraction, and multiplication. This approach not only helped to concretize abstract mathematical concepts but also enhanced the engagement, independence, and motivation of students who are slow learners. The learning environment became more positive and interactive, fostering greater student participation. In conclusion, this study highlights the importance of incorporating environment-based manipulative media and providing tailored scaffolding to support inclusive mathematics learning in elementary schools, particularly in resource-limited contexts. The findings may serve as a reference for educational development in Indonesia, underscoring the need for educators and policymakers to design adaptive and equitable learning strategies that meet the diverse needs of all students.
Keywords: conceptual understanding, number operations, manipulative media, slow learners, inclusive education.
Aghisni, Maharani, F. S., Nugraha, F. I., Gunawan, W. A., Seti, & Setiawati, D. (2025). Peningkatan metode pembelajaran kontekstual untuk meningkatkan motivasi belajar anak slow learner di sekolah dasar kelas 5 sdn 1 jamblang [Improving contextual learning methods to increase learning motivation of slow learners in grade 5 elementary school, SDN 1 Jamblang]. Journal on Education, 07(02), 12179–12191.
Ambarwati, Kurnia, I., & Wenda, D. D. N. (2022). Pentingnya media pembelajaran pada materi pipalanda untuk siswa slow learner usia 9-12 tahun di kecamatan semen kabupaten kediri [The importance of learning media in pipalanda material for slow learner students aged 9-12 years in semen district, kediri regency]. Seminar Nasional Sains, Kesehatan, Dan Pembelajaran, 2(1), 261–272.
Angraini, L. M., Larsari, V. N., Muhammad, I., & Kania, N. (2023). Generalization and analogical reasoning of junior high school viewed from bruner’s learning theory. Infinity Journal, 12(2), 291–306. https://doi.org/10.22460/infinity.v12i2.p291-306
Antara, I. G. W. S., Widiana, I. W., & Jampel, I. N. (2024). Assistive Technology in Mathematics Education: Investigating the Effectiveness of Math Manipulatives for Students with Disabilities. International Journal of Elementary Education, 8(3), 519–527. https://doi.org/10.23887/ijee.v8i3.85378
Aprinastuti, C., Anggadewi, B. E. T., Suharno, R., & Wiyantari, W. (2020). Development of mathematics manipulative for slow learner and dyscalculia student in elementary school by using Montessori’s characteristic. Journal of Physics: Conference Series, 1663(1). https://doi.org/10.1088/1742-6596/1663/1/012065
Ardhia, W. P., Patonah, S., Sumarmiyati, & Faizah, M. (2024). Penerapan media stik es krim untuk meningkatkan aktivitas hasil belajar matematika siswa kelas i sekolah dasar [Application of ice cream stick media to improve mathematics learning outcomes of first grade elementary school students]. Majalah Lontar Universitas PGRI Semarang, 36(1), 37–47.
Bartolini, M. G., & Martignone, F. (2014). Manipulatives in mathematics education. In S. Lerman (Ed.), Encyclopedia of Mathematics Education (pp. 365–463). Springer.
Bintang, J. M., Kusuma, K. T., & Nugraha, K. W. (2024). peran media pembelajaran dalam meningkatkan hasil belajar siswa slow learner [The role of learning media in improving learning outcomes of slow learner students]. Tarbi: Jurnal Ilmiah Mahasiswa, 3(2), 237–254. https://doi.org/10.31004/basicedu.v5i3.886
Creswell, J. W. (2014). Research design: qualitative, quantitative, and mixed methods approaches (V. Knight, Ed.; 4th ed.). SAGE Publications.
Creswell, J. W., & Creswell, J. D. (2018). Qualitative, quantitative, and mixed methods approaches (Helen Salmon, Chelsea Neve, Megan O’Heffernan, David C. Felts, & Amy Marks, Eds.; Fifth). SAGE.
D’Antonio, F., Boccia, M., Di Vita, A., Suppa, A., Fabbrini, A., Canevelli, M., Caramia, F., Fiorelli, M., Guariglia, C., Ferracuti, S., de Lena, C., Aarsland, D., & ffytche, D. (2022). Visual hallucinations in Lewy body disease: pathophysiological insights from phenomenology. Journal of Neurology, 269(7), 3636–3652. https://doi.org/10.1007/s00415-022-10983-6
Darmayanti, R., Utomo, D. P., Choirudin, C., Usmiyatun, U., & Nguyen, P. T. (2023). Bruner’s theory on the development of e-book traditional snacks ethnomathematics for mathematical understanding ability. Alifmatika: Jurnal Pendidikan Dan Pembelajaran Matematika, 5(1), 21–39. https://doi.org/10.35316/alifmatika.2023.v5i1.21-39
Derzhavina, V. V., Nikitina, A. A., Makarov, A. L. M., Piralova, O. F., Korzhanova, A. A., Gruver, N. V., & Mashkin, N. A. (2021). Inclusive Education: Importance and problems for students' social integration. Propósitos y Representaciones, 9(SPE3). https://doi.org/10.20511/pyr2021.v9nspe3.1130
Dethan, H. H., Pradipto, A. B., Naen, A. B., Dosinaeng, W. B. N., & Djong, K. D. (2022). Peningkatan aktivitas belajar dan hasil belajar operasi bilangan bulat melalui media kerang [Improving learning activities and learning outcomes of integer operations through shell media]. Jurnal Media Edukasi Dan Pembelajaran, 1(Desember), 158–169.
Donath, J. L., Lüke, T., Graf, E., Tran, U. S., & Götz, T. (2023). Does professional development effectively support the implementation of inclusive education? a meta-analysis. Educational Psychology Review, 35(1). https://doi.org/10.1007/s10648-023-09752-2
Fitriana, D., Putri, R. I., FajriN, E., & Shoriah, K. A. (2024). Tinjauan terhadap paradigma pengembangan anak: strategi pendidikan untuk memperkuat potensi siswa slow learner Di SDN 03 Alai [A review of child development paradigms: educational strategies to strengthen the potential of slow learner students at SDN 03 Alai]. INNOVATIVE: Journal Of Social Science Research, 5, 6310–6325.
Gonthier, C. (2022). Cross-cultural differences in visuo-spatial processing and the culture-fairness of visuo-spatial intelligence tests: an integrative review and a model for matrices tasks. In Cognitive Research: Principles and Implications (Vol. 7, Issue 1). Springer Science and Business Media Deutschland GmbH. https://doi.org/10.1186/s41235-021-00350-w
Gonzales, G. (2022). Mapping pupils’ learning progression using hand manipulatives and touch screen applications: implications for the post-covid-19 new normal. Education Research International, 2022. https://doi.org/10.1155/2022/9976083
Handayani, P., Wardhani, P. A., & Wardatussa’idah, I. (2024). Analisis penerapan pembelajaran berdiferensiasi pada peserta didik slow learner dalam belajar matematika [Analysis of the application of differentiated learning for slow learner students in learning mathematics]. Pendas: Jurnal Ilmiah Pendidikan Dasar, 9(2), 6147–6159.
Hankeln, C. (2024). Challenges in using chatgpt for assessing conceptual understanding in mathematics education. Journal of Mathematics Education, 17(1), 1–15. https://doi.org/10.26711/007577152790171
Hernández-Torrano, D., Somerton, M., & Helmer, J. (2022). Mapping research on inclusive education since the Salamanca Statement: a bibliometric review of the literature over 25 years. International Journal of Inclusive Education, 26(9), 893–912. https://doi.org/10.1080/13603116.2020.1747555
Hikma, N. A., Hafidzah, Z. M., & Dewina, Z. (2025). Pendekatan guru dalam mengidentifikasi dan mendukung peserta didik berkebutuhan khusus slow learner di sekolah dasar [Teachers' approaches in identifying and supporting slow learners with special needs in elementary schools]. Education Achievement: Journal of Science and Research, 6(1), 297–310. http://pusdikra-publishing.com/index.php/jsr
Irmayani, N. D., Niswatun, H., Munandar, A. I., & Hidayati, D. (2024). Efektivitas penggunaan media manipulatif melalui pendekatan rme untuk meningkatkan kemampuan berhitung siswa SD/MI [The effectiveness of using manipulative media through the rme approach to improve elementary school/islamic elementary school students' arithmetic skills]. Atmosfer: Jurnal Pendidikan, Bahasa, Sastra, Seni, Budaya, Dan Sosial Humaniora, 2(4), 411–423. https://doi.org/10.59024/atmosfer.v2i4.1114
Irshid, M. M. B., Khasawneh, A. A., & Al-Barakat, A. A. (2023). The effect of conceptual understanding principles-based training program on enhancement of pedagogical knowledge of mathematics teachers. Eurasia Journal of Mathematics, Science and Technology Education, 19(6). https://doi.org/10.29333/ejmste/13215
Isnaniah, & Imamuddin, M. (2020). Students’ understanding of mathematical concepts using manipulative learning media in elementary schools. Journal of Physics: Conference Series, 1471(1). https://doi.org/10.1088/1742-6596/1471/1/012050
Jannah, U. R., Basri, H., Hafsi, A. R., Linarsih, Y., & Utami, M. R. (2021). Understanding concepts of multiplication number for slow learner students through meaningful learning at an inclusion school. Proceedings of the 2nd International Conference on Innovation in Education and Pedagogy (ICIEP 2020), 619, 273–279.
Jannah, U. R., Basri, H., Rahmad, Dewi, N. P., Hafsi, A. R., Ikram, M., Nurhidayati, S., Rizqiyah, T., Sholihah, W., & Rifanda, A. R. (2025). Integrating learning trajectories into individualized education programs: A development method for inclusive elementary schools. Multidisciplinary Science Journal.
Jannah, U. R., Hafsi, A. R., Hasanah, S. I., Basri, H., Nurhidayati, S., Rifanda, A. R., & Agustin, S. P. D. (2025). STEM: Project-based learning to enhance conceptual understanding of two-dimensional shapes and develop the pancasila student profile. Premiere Educandum: Jurnal Pendidikan Dasar Dan Pembelajaran, 14(2). https://doi.org/10.25273/pe.v14i2.21314
Jannah, U. R., Hafsi, A. R., & Nurhidayati, S. (2023). Conceptual understanding of students with special needs in two-dimensional shapes based on pirie kieren’s theory. Jurnal Tadris Matematika, 6(2), 219–230. https://doi.org/10.21274/jtm.2023.6.2.219-230
Jannah, U. R., Mashurat, M., Ghafur, A., Kiptiyah, R., Astutik, D. P., & Sucahyono, H. (2023). Pemahaman konsep matematika siswa sekolah dasar melalui media “kulit kerang” dalam kegiatan lesson study untuk penguatan profil pelajar pancasila [Elementary school students' understanding of mathematical concepts through "seashell" media in lesson study activities to strengthen the pancasila student profile]. Prosiding Seminar Nasional Kemitraan Dosen Lembaga Pendidikan Tenaga Kependidikan (LPTK) Dengan Guru Di Sekolah Tahun 2023, 393–404. https://dikti.kemdikbud.go.id/pengumuman/prosiding-seminar-nasional-kemitraan-dosen-lptk-dengan-guru-di-sekolah-tahun-2023/
Jannah, U. R., Putra, F. P. E., Hafsi, A. R., & Basri, H. (2021). Pengembangan sekolah inklusi dengan pemanfaatan media visual scratch dan alat peraga manipulatif [Development of inclusive schools by utilizing scratch visual media and manipulative teaching aids]. Wikrama Parahita: Jurnal Pengabdian Masyarakat, 5(1), 89–96. https://doi.org/10.30656/jpmwp.v5i1.2653
Jannah, U. R., Saleh, H., & Wahidah, A. (2019). Scaffolding untuk pembelajaran matematika di kelas inklusi [Scaffolding for mathematics learning in inclusive classrooms]. JKPM (Jurnal Kajian Pendidikan Matematika), 5(1), 61–72. http://journal.lppmunindra.ac.id/index.php/jkpm/
Jonsson, B., Wiklund-Hörnqvist, C., Stenlund, T., Andersson, M., & Nyberg, L. (2021). A learning method for all: The testing effect is independent of cognitive ability. Journal of Educational Psychology, 113(5), 972–985.
Joseph, B., & Abraham, S. (2023). Identifying slow learners in an e-learning environment using k-means clustering approach. Knowledge Management and E-Learning, 15(4), 539–553. https://doi.org/10.34105/j.kmel.2023.15.031
Khaira, U., & Herman, T. (2020). Assessment processes for slow learners in mathematics learning. Journal of Physics: Conference Series, 1521(3). https://doi.org/10.1088/1742-6596/1521/3/032097
Kholid, M. N., Imawati, A., Swastika, A., Maharani, S., & Pradana, L. N. (2021). How are students’ conceptual understanding for solving mathematical problem? Journal of Physics: Conference Series, 1776(1). https://doi.org/10.1088/1742-6596/1776/1/012018
Krämer, S., Möller, J., & Zimmermann, F. (2021). Inclusive education of students with general learning difficulties: a meta-analysis. Review of Educational Research, 91(3), 432–478. https://doi.org/10.3102/0034654321998072
Lafay, A., Osana, H. P., & Valat, M. (2019). Effects of interventions with manipulatives on immediate learning, maintenance, and transfer in children with mathematics learning disabilities: a systematic review. In Education Research International (Vol. 2019). Hindawi Limited. https://doi.org/10.1155/2019/2142948
Lambert, R. (2017). ‘When I am being rushed, it slows down my brain’: constructing self-understandings as a mathematics learner. International Journal of Inclusive Education, 21(5), 521–531. https://doi.org/10.1080/13603116.2016.1251978
Leow, S. H., & Kaur, B. (2024). Study of grade two students solving a non-routine problem with access to manipulatives. International Journal of Science and Mathematics Education, 22, 1457–1478.
Lin Sen, G., AmilinTengah, K., Shahrill, M., & Leong, E. (2017). Teaching and learning of integers using hands-on versus virtual manipulatives. Proceedings of the 3rd International Conference on Education, 174–185. https://doi.org/10.17501/icedu.2017.3119
Listiawati, N., Sabon, S. S., Siswantari, Subijanto, Wibowo, S., Zulkardi, & Riyanto, B. (2023). Analysis of implementing Realistic Mathematics Education principles to enhance mathematics competence of slow learner students. Journal on Mathematics Education, 14(4), 683–700. https://doi.org/10.22342/jme.v14i4.pp683-700
Luzano, J. F. P. (2023). The interplay of conceptual understanding and problem-solving competence in mathematics. International Journal of Multidisciplinary Approach and Studies, 10(2), 89–97. https://www.researchgate.net/publication/369982234
Magdum, R., Jadhav, P., Magdum, A., Shirguppikar, S., Deasavale, R., & Khot, S. (2025). Enhancing learning outcomes: the impact of competition on slow learners' engagement and academic performance. Journal of Engineering Education Transformations, 38(2), 458–462.
Mendoza, M., & Heymann, J. (2022). Implementation of inclusive education: a systematic review of studies of inclusive education interventions in low- and lower-middle-income countries. International Journal of Disability, Development and Education, 71(3), 1–19. https://doi.org/10.1080/1034912X.2022.2095359
Muis, M. (2023). Penerapan media stik es krim dalam pembelajaran matematika penjumlahan dan pengurangan pada kelas i di mi-persmin wonokromo surabaya. IBTIDA’IY : Jurnal Prodi PGMI, 8(1), 15–20. https://doi.org/10.31764
Murdiyanto, T., Wijayanti, D. A., & Sovia, A. (2023). Identify slow learners in math: case study in rural schools. International Journal of Interactive Mobile Technologies, 17(6), 45–61. https://doi.org/10.3991/ijim.v17i06.36903
Nasayao, R. A., & Lingo, J. T. (2023). Improving students’ attitudes and conceptual understanding in mathematics using different teaching strategies. In International Journal of Membrane Science and Technology (Vol. 10, Issue 3).
Ndasi, A. A. R., Jaun, A. Y. R., & Wewe, M. (2024). Penerapan media manipulatif untuk meningkatkan numerasi siswa kelas V Di SDK Waerana II [Implementation of manipulative media to improve numeracy of fifth grade students at SDK Waerana II]. Jurnal Ilmiah Mandalika Education (MADU), 2(1), 383–391. https://permatamandalika.com/index.php/MADU
Nilholm, C. (2021). Research about inclusive education in 2020 How can we improve our theories in order to change practice? European Journal of Special Needs Education, 36(3), 358–370. https://doi.org/10.1080/08856257.2020.1754547
Nurjanah, Dahlan, J. A., & Wibisono, Y. (2020). The effect of hands-on and computer-based learning activities on conceptual understanding and mathematical reasoning. International Journal of Instruction, 14(1), 143–160. https://doi.org/10.29333/IJI.2021.1419A
Ozawa, S., Laing, S. K., Higgins, C. R., Yemeke, T. T., Park, C. C., Carlson, R., Ko, Y. E., Guterman, L. B., & Omer, S. B. (2022). Educational and economic returns to cognitive ability in low- and middle-income countries: A systematic review. World Development, 149. https://doi.org/10.1016/j.worlddev.2021.105668
Pant, B. P., Dahal, N., & Luitel, B. C. (2024). Teachers’ narratives on integrating geogebra for enhancing conceptual understanding in mathematics. In W.-C. Yang, D. Meade, & W. K. HO (Eds.), Proceedings of the 29th Asian Technology Conference in Mathematics (pp. 411–419). Mathematics and Technology, LLC.
Parhizkar, B. (2021). The design and development of motion detection edutainment maths for use with slow learners’ children. The University of Nottingham.
Park, J., Bryant, D. P., & Shin, M. (2022). Effects of interventions using virtual manipulatives for students with learning disabilities: a synthesis of single-case research. Journal of Learning Disabilities, 55(4), 325–337. https://doi.org/10.1177/00222194211006336
Permatasari, D., Rantayu, R. F., Farida, A., Salsabila, Z., & Muwaffiq, M. N. (2022). Pendampingan belajar matematika bagi siswa berkebutuhan khusus slow learner [Mathematics learning assistance for slow learners with special needs]. Jurnal Penamas Adi Buana, 6(1), 37–44. http://jurnal.unipasby.ac.id/index.php/penamas
Pfister, M., Moser Opitz, E., & Pauli, C. (2015). Scaffolding for mathematics teaching in inclusive primary classrooms: a video study. ZDM - Mathematics Education, 47(7), 1079–1092. https://doi.org/10.1007/s11858-015-0713-4
Putri, A. Y., Mariana, N., & Muhimmah, H. A. (2024). Eksplorasi kemampuan numerasi pada anak lamban belajar di kelas awal: studi kasus di sekolah dasar [Exploring numeracy skills in slow learners in early grades: a case study in elementary school]. Jurnal Pendidikan dan Pembelajaran Indonesia (JPPI), 4(4), 1555–1563. https://doi.org/10.53299/jppi.v4i4.851
Rahayu, N. P., Prastiwi, L., & Setiawan, W. (2024). Improving the numeracy skills of slow learners with ice cream stick media: single subject research. EDUMATSAINS: Jurnal Pendidikan Matematika Dan Sains, 9(1), 235–245. https://doi.org/10.33541/edumatsains
Ramananda, P. C., Arifin, S., & Septy, L. (2024). Kemampuan pemahaman konsep siswa dengan pembelajaran guided discovery learning [Students' conceptual understanding ability with guided discovery learning]. SJME (Supremum Journal of Mathematics Education), 8(1), 129–141. https://doi.org/10.35706/sjme.v8i1.10081
Sahithya, B. R., & Raman, V. (2021). Parenting style, parental personality, and child temperament in children with anxiety disorders a clinical study from India. Indian Journal of Psychological Medicine, 43(5), 382–391. https://doi.org/10.1177/0253717620973376
Sari, Z. P., Sarofah, R., & Fadli, Y. (2022). The implementation of inclusive education in indonesia: challenges and achievements. Journal of Public Policy, 8(4), 264. https://doi.org/10.35308/jpp.v8i4.5420
Septiani, B., Hermansah, B., & Ayu, I. R. (2024). Penerapan media pembelajaran stik es krim untuk meningkatkan hasil belajar matematika Di SD Negeri 59 Palembang [The application of ice cream stick learning media to improve mathematics learning outcomes at public elementary school 59 Palembang]. Didaktik: Jurnal Ilmiah PGSD FKIP Universitas Mandiri, 10(4), 1–9.
Setyawan, F., Andriyani, Handayani, T. K., Ratih, K., Sutopo, A., Rusli, T. I., & Alfiany, N. R. (2021). Rigorous thinking in mathematics modelling for slow learners. Journal of Physics: Conference Series, 1720(1). https://doi.org/10.1088/1742-6596/1720/1/012005
Sholihah, S., & Trimurtini. (2023). Implementasi teori bruner pada bilangan pecahan melalui model luas dan model panjang [Implementation of bruner's theory on fractional numbers through area model and length model]. Jurnal Pendidikan Mipa, 13(1), 124–133. https://doi.org/10.37630/jpm.v13i1.850
Singh, J., Arun, P., & Bajaj, M. K. (2021). Theory of mind and executive functions in children with attention deficit hyperactivity disorder and specific learning disorder. Indian Journal of Psychological Medicine, 43(5), 392–398. https://doi.org/10.1177/0253717621999807
Sintawati, M., Sukma, H. H., & Marini, A. (2022). Mathematics pedagogical knowledge for slow learners teaching. AIP Conference Proceedings.
Sintawati, M., Sukma, H. H., Mardati, A., Feruzi, S. M., & Satrianawati, S. (2024). Pre-service teachers’ pedagogical knowledge and attitudes towards slow learner students. Journal of Education and Learning, 18(4), 1117–1124. https://doi.org/10.11591/edulearn.v18i4.21626
Sovia, A., & Herman, T. (2020). Gesture of slow learner student in mathematical Communication. Journal of Physics: Conference Series, 1464(1). https://doi.org/10.1088/1742-6596/1464/1/012046
Susilo, C. Y., & Prihatnani, E. (2022). Scaffolding for slow learner children on integer operations. Kreano: Jurnal Matematika Kreatif-Inovatif, 13(1), 113–125. http://journal.unnes.ac.id/nju/index.php/kreano
Ulyani, O., & Qohar, A. (2021). Development of manipulative media to improve students’ motivation and learning outcomes on the trigonometry topic. AIP Conference Proceedings, 2330. https://doi.org/10.1063/5.0043142
Ummah, S. K., In’am, A., & Azmi, R. D. (2019). Creating manipulatives: improving students’ creativity through project-based learning. Journal on Mathematics Education, 10(1), 93–102.
UNESCO. (2008). Inclusive education: the way of the future. International Conference on Education.
Uwineza, I., Uworwabayeho, A., & Yokoyama, K. (2023). Grade-3 learners’ performance and conceptual understanding development in technology-enhanced teaching with interactive mathematics software. European Journal of Educational Research, 12(2), 759–774. https://doi.org/10.12973/eu-jer.12.2.759
van de Pol, J., Volman, M., & Beishuizen, J. (2010). Scaffolding in teacher-student interaction: A decade of research. In Educational Psychology Review (Vol. 22, Issue 3, pp. 271–296). https://doi.org/10.1007/s10648-010-9127-6
van Oers, B. (2019). Scaffolding in mathematics education. In Encyclopedia of Mathematics Education (pp. 1–4). Springer International Publishing. https://doi.org/10.1007/978-3-319-77487-9_136-2
Refbacks
- There are currently no refbacks.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.