Born in Medan on January 24th, 1987, Rully Charitas Indra Prahmana is the second child of his late father, Narli and his mother, Milli Eko Suryani. He finished his study in elementary, junior, and senior high school in his hometown, Medan. Soon, after graduated from senior high school, he continued his study at the bachelor program of Mathematics, Universita Gadjah Mada within three years and eight months with "highly satisfactory" predicate. His final project was entitled Crank-Nicholson Finite Difference Method for Determining Option Pricing using The Black-Scholes Model. His research experience was then continued in the LabMath-Indonesia, Bandung, for around 6 months under the supervision of Dr. Ardhasena Sopaheluwakan and Prof. Brenny van Groesen (University of Twente), with the topic of Water Wave Equations. Furthermore, the result experience continues in the Universitas Parahyangan, Bandung, for around 1 month, under the supervision of Dr.ir. M. H. Michel Vellekoop (University of Twente), Dr. Ferry Jaya Permana (Universitas Katolik Parahyangan), and Dr. Hans Van M (TU Delft), with the topic of Shout Options. In 2010, he got a scholarship to the Bilingual Master Program on Mathematics Education (BiMPoME) which was collaboration with the Directorate General of Higher Education, Sriwijaya University, and Utrecht University. He completed the study in one and a half year with summa cum laude recognition and awarded as the Best Graduated in Graduate School of Sriwijaya University. His thesis title was Designing Numbers Operation Learning using Traditional Games “Tepuk Bergambar” for Third Grade Elementary School Students. On September 21st, 2012, he got a chance to continue his study of Ph.D. Program in Mathematics Education at the Middle East Technical University, Turkey under the full scholarship from the Turkish government. However, he decided not to accept the scholarship and chose to married Rina Sri Kalsum Siregar on September 29th, 2012. Currently, he has two children namely Muhammad Zuna Prahmana Saragih (July 15th, 2013) and Quthbie Shofwan Saragih (October 9th, 2014). A year later, in July 2013, he got another chance to continue his study. It was the BPP-DN scholarship for the doctoral program of mathematics education in Universitas Pendidikan Indonesia (UPI). He completed his doctoral program in less than three years and became the first graduate in his batch. His dissertation was on the topic of Local Instructional Theory on Research in Mathematics Education to Enhance Research and Academic Writing Skills for Pre-Service Mathematics Teacher, under the supervision of Prof. Yaya S. Kusumah, M.Sc., Ph.D. and Prof. Dr. Darhim, M.Si. After the study, he is still active in giving studium generale, becoming a speaker in the various national seminar, and becoming a trainer in the management of open journal system (OJS) in several universities and colleges. Some of the universities are Universitas Islam Negeri Syarif Hidayatullah, Universitas Islam Negeri Raden Fattah, Universitas Islam Negeri Sultan Syarif Kasim, Universitas Islam Negeri Sunan Kalijaga, Universitas Islam Negeri Sultan Maulana Hasanuddin, Universitas Islam Negeri Sunan Ampel, Universitas Pattimura, Universitas Subang, Universitas Hamzanwadi, Universitas Sultan Ageng Tirtayasa, Universitas Negeri Medan, Universitas Padjajaran, Universitas Muhammadiyah Tangerang, Universitas Negeri Padang, Universitas Negeri Gorontalo, Universitas Riau, Universitas Gadjah Mada, Universitas Siliwangi, Universitas Padjajaran, Universitas Papua, Universitas Negeri Manado, Universitas Sarjanawiyata Tamansiswa, Universitas Lambung Mangkurat, and Universitas Sriwijaya. Furthermore, several colleges and institute are STKIP Siliwangi, STKIP Bina Bangsa Getsempena, STKIP Surya, and Institut Teknologi Bandung. He often presents his work in various national and international conferences. Some of the conferences are Konferensi Nasional Matematika (KNM), Konferensi Nasional Pendidikan Matematika (KNPM), South East Asian Design/Development Research Conference (SEA-DR), Asian Mathematical Conference (AMC), The International Symposium on Mathematics Education Innovation (ISMEI), Ahmad Dahlan International Conference on Mathematics and Mathematics Education (AD INTERCOMME), and IndoMS International Conference on Mathematics and Its Applications (IICMA). So far, he has written numerous books that can be found either in bookstores or through online search. His research publication can be found in his profile on Research Gate, Google Scholar, and Scopus. He is active as a lecturer and a researcher at the Master Program in Mathematics Education of Universitas Ahmad Dahlan, Yogyakarta, and a member of Indonesian Mathematical Society (IndoMS). In addition, he is also a Managing Editor of the Journal on Mathematics Education (JME) and the International Journal on Emerging Mathematics Education (IJEME) which has scope particularly in mathematics education.