Key findings:

The key findings of this R&D study on mathematics learning tools development are: the tools, including Lesson Implementation Plans (RPP), Student Worksheets (LKPD), and Teaching Modules, were validated with high scores for content and construct validity. The average validity scores indicated that the developed tools met the criteria for validity in enhancing students' mathematical creative thinking skills.

What is known and what is new?

The known aspect in this abstract is the use of the Plomp model for developing educational resources. The new contribution is the application of this model to create valid mathematics learning tools focused on sequences and series, with the specific aim of enhancing students' mathematical creative thinking skills, which represents an innovative approach to teaching and learning in this domain.

What is the implication, and what should change now?

The implication of this R&D study is the successful development of valid mathematics learning tools to enhance students' creative thinking skills in sequences and series. Changes needed include further validation through pilot testing to ensure the effectiveness of these tools in improving students' mathematical creativity and learning outcomes in real classroom settings.

The 21st century has been marked by the use of information and communication technology in all aspects of life, including the learning process [1]. In the midst of this rapid change, education is faced with both challenges and opportunities for transformation. On the one hand, 21st century developments require the education system to adapt. Technological advances have given rise to new ways of learning, from online platforms to artificial intelligence. On the other hand, education plays an important role in shaping a resilient and adaptive 21st century society. Critical, creative, and innovative thinking skills are needed to solve complex challenges.

Creative thinking is a process used when we come up with a new idea. It combines previously unconnected ideas. Creative thinking, when combined with critical thinking, is a manifestation of higher order thinking. There are two perspectives on creative thinking. The first view is that creative thinking is intuitive, in contrast to critical (analytical) thinking, which is based on logic. The second view is that creative thinking is a combination of analytical and intuitive thinking [2, 3]. Based on research results presented by [4, 5], one way to improve creative thinking skills is through literacy.

Literacy is often associated with letters or alphabets. Literacy is an adaptation of the English word "literacy", which means the ability to read and write. According to the Usaid Prioritas program (2014), early grade literacy only refers to a person's language skills (listening, speaking, reading, and writing) to communicate in different ways according to their purpose. Thus, literacy is only associated with the ability to communicate in writing.

Mathematical literacy based on PISA studies includes four mathematical contents, namely (a) space and shape, (b) change and relationship, (c) quantity, and (d) uncertainty and data. The content of space and shape is one of the contents in PISA that uses geometry material as the basis for its solution. Of the four contents, the content of space and shape or those related to geometry occupy the lowest position [6-8]. However, this literacy skill, especially geometry literacy, is one of the important skills that must be mastered by students to face the challenges of today. The indicators of geometry literacy are broken down from mathematical literacy, namely formulate, employ, interpret and evaluate. Based on this, efforts are needed to support students' literacy skills. One effort that can be made is to develop learning tools based on mathematical literacy.

Teachers have the main task of planning, implementing, and evaluating the learning process. Hala (2015) [9]  states that teachers plan their learning by creating and preparing learning tools. Then, the learning tools are used to carry out the learning process and then conduct an evaluation to see whether the learning objectives have been achieved or not. Improving the quality of learning and learning outcomes requires aligning the learning process supported by good tools by developing learning tools. [10].

The low results of AKM (Assesmen Kompetensi Minimum) are due to the weak mathematical literacy where students do not yet have the ability to understand and apply mathematical concepts used to solve problems in everyday life.

Previous studies have developed teaching materials to train mathematical literacy skills, including those by Octaviyani, Putri, & Yanawati (2019); Susanta, Sumardi, & Zulkardi (2022) [11, 12]. These teaching materials are in the form of student worksheets. In contrast to previous research, this study develops a learning device in the form of a Validated Learning Implementation Plan (RPP), Student Worksheets (LKPD), and Teaching Modules based on validator assessments. These materials can be used to train students' creative thinking skills in the material of sequences and series.

This research is a research and development (R&D) study that aims to develop a mathematical literacy-based learning device to train students' creative thinking skills in the material of sequences, series, and measurement. The learning device is considered valid if it meets the criteria set by two validators.

The developed mathematical learning device consists of a Learning Implementation Plan (RPP), Student Worksheets (LKPD), and Teaching Modules. The development model used in this research is the Plomp model, which consists of five phases: preliminary investigation, design, realization/construction, test, evaluation, and revision. The modification made in this research is to simplify the Plomp model from five phases to four phases: preliminary investigation, design, realization, and test, evaluation, and revision. The implementation phase is not explicitly carried out but is integrated into the research implementation, namely when conducting field trials of the learning device in the research subject's scope. Implementation in a wider scope is not carried out in this research due to time constraints. The following diagram illustrates the Plomp stages: Fig 2.1

Based on the learning device development flow in Figure 2.2, other modifications of the learning model proposed by Plomp can be seen. After the learning device is declared valid by both validators, it is then followed by a trial of the learning device. If the first trial does not meet the effectiveness criteria, then a second trial is conducted, and so on until the learning device meets the effectiveness criteria.

The validation data collection techniques and instruments are the Learning Implementation Plan (RPP) Validation Sheet, the Student Worksheet (LKPD) Validation Sheet, and the Teaching Module Validation Sheet. These three instruments are used by experts/validators to assess the validity of the validated learning device, which consists of the Learning Implementation Plan (RPP), LKPD, and Teaching Module, and to revise the three devices if there are any improvements.

Data validation analysis is performed by determining the validity category of each criterion, aspect, or overall aspect by matching the criterion average (Ki), aspect average (Ai), or total average (X with the established validity category. The validity category of each criterion, each aspect, or overall aspect is determined [13] as follows:

3,5 ≤M≤4         Highly Valid

2,5≤M<3,5  Valid

1,5≤M<2,5  Sufficiently Valid

M<1,5  Not Valid

This section presents the development phases of mathematical literacy-based learning devices to train students' mathematical creative thinking skills in the material of sequences and series. The learning device development model used is based on the development model proposed by Plomp, which consists of (a) preliminary investigation, (b) design, (c) realization, and (d) testing, evaluation, and revision.

Preliminary Investigation Results

Preliminary investigation was conducted to identify the problems faced by teachers of SMK Kartika XX-1 Makassar, especially mathematics teachers who teach in grade X. Based on the results of discussions with mathematics teachers of SMK Kartika Makassar about mathematics learning activities in the school, it was found that the learning process is still centered on the teacher. Teachers tend to dominate the learning process so that students are not active in learning in the classroom. This is evidenced by the large number of students who do not participate in the teaching and learning process. Meanwhile, based on the theories that are currently developing, it is highly recommended to conduct learning that can involve and activate students. In addition to the learning process still being centered on the teacher, in the learning process the teacher has not fully included mathematical literacy content, although mathematical literacy is one of the learning objectives. This is due to the lack of learning media that supports the development of students' mathematical literacy.

Design Phase Results

The development results of this phase are preliminary designs that cover three aspects: (1) Preliminary Design of Learning Implementation Plan (RPP), (2) Preliminary Design of Student Worksheets (LKPD), (3) Preliminary Design of Teaching Modules.

Realization/Construction Phase Results

The results obtained in phases 1 and 2 were further refined, discussed with experts, and reviewed. This activity was carried out in phase 3 in order to compile and realize the developed learning devices consisting of Learning Implementation Plan (RPP), Student Worksheets (LKPD), and Teaching Modules.

Test, Evaluation, and Revision Phase Results

The results of this phase are to determine whether the learning devices that have been designed and compiled in detail in the second and third phases are feasible according to expert judgment. Expert judgment includes the validity of the developed product. The validation results and revisions can be seen in the following table:

Table 3.1 Names of Validators

Table 3.2 Suggestions for First Validation Improvement by the Validation Team

Table 3.3 Suggestions for Second Validation Improvement by the Validation Team

Table 3.4 Results of the Validation Team's Assessment Analysis

Table 3.5 Summary of the Validation Team's Assessment Analysis Results

Based on this research, it is known that the quality of the learning materials in the form of Lesson Plans (RPP), Student Worksheets (LKPD), and Teaching Modules meets the validity criteria. The validity criteria are obtained from the assessment of experts based on indicators of suitability with needs, strong theoretical foundation, and consistency between the components of the developed teaching materials [14]. Validity can be described as the core of the development process, especially for measuring abstract or unobservable concepts [15]. According to Mustami (2017) [16], the aspects that need to be considered in validating learning materials are the construction of content/material, completeness of presentation techniques, integration, language, and benefits/usefulness [16]. (Table 3.1 and 3.2)

In addition to the validity criteria, the quality of learning materials is also assessed based on the effectiveness criteria. The effectiveness of a product can be seen from the ease of using the product being developed [17]. Products that meet the very valid criteria will be very easy to use and utilize in the learning process [11, 18]. It is important to consider the practicality criteria of a product before it is used [19], both in terms of the practicality of preparation, use, and interpretation of the product [20]. After considering the validity and practicality of a product being developed, the next step is to consider the effectiveness criteria to determine whether the learning objectives have been achieved [17, 21] which are oriented towards the process and results. (Table 3.3)

Based on the results of the validity analysis from the validators, the following validation results were obtained for several validity instruments: Lesson Plan (RPP),  Average score of 3.58, Student Worksheet (LKPD), Average score of 3.56, Teaching Module, Average score of 3.56. Each of these validity instruments falls into the highly valid category, except for the learning outcome test which falls into the valid category. Therefore, the developed learning materials meet the validity criteria. (Table 3.4)

This research is in line with the research conducted by Sumirattana, Makanong, & Thipkong (2017) [22] which showed that presenting problems related to students' real lives and directing them to solve the problems individually or in groups can improve students' mathematical literacy skills. Additionally, research by Widi et al., (2019); Susanta & Sumardi, (2022) [12, 23] found that developing modules using problems that are close to students' environment during the learning process can support students' literacy and creative thinking skills. (Table 3.5)

The validation results of several validation instruments, including the Lesson Plan (RPP), Student Worksheet (LKPD), and Teaching Module, showed that each of these validation instruments falls into the highly valid category. Therefore, the developed mathematics learning materials meet the validity criteria.

6.Funding: No funding sources.

7. Conflict of interest: None declared.

8. Ethical approval: The study was approved by the Institutional Ethics Committee of Universitas Negeri Makassar.

1. Daryanto, & Syaiful K. Pembelajaran Abad 21. Gava Media, (2016).
2. Barak, Moshe, and Yaron Doppelt. "Using portfolios to enhance creative thinking." Journal of Technology Studies 26.2 (2000): 16-25. https://doi.org/10.21061/jots.v26i2.a.3
3. Krummheuer, Götz, et al. "Explaining the mathematical creativity of a young boy: an interdisciplinary venture between mathematics education and psychoanalysis." Educational Studies in Mathematics 84 (2013): 183-199. https://doi.org/10.1007/s10649-013-9505-3
4. Amar, Ghoffar Ismail. "The Use of Creative Problem Solving Based Genetic Mutation Module in Higher Education." International Journal of Higher Education 10.3 (2021): 33-45. . https://doi.org/10.5430/ijhe.v10n3p33.
5. Dosinaeng, Wilfridus Beda Nuba. "Analysis of students’ higher order thinking skills in solving basic combinatorics problems." Math Didactic: Jurnal Pendidikan Matematika 5.2 (2019): 133-147.  https://doi.org/10.33654/math.v5i2.611
6. Mahdiansyah, Mahdiansyah, and Rahmawati Rahmawati. "Literasi matematika siswa pendidikan menengah: analisis menggunakan desain tes internasional dengan konteks Indonesia 1." Literasi Matematika Siswa Pendidikan Menengah: Analisis Menggunakan Desain Tes Internasional dengan Konteks Indonesia 1 20.4 (2014): 452-469. https://repositori.kemdikbud.go.id/540/1/2.%20mahdiansyah.pdf 
7. Nurutami, Aulia, and Fariz Setyawan. "Kemampuan literasi matematika siswa berdasarkan konten PISA." Wacana Akademika: Majalah Ilmiah Kependidikan 3.1 (2019): 11-20. https://doi.org/10.30738/wa.v3i1.3216
8. Oktaviana, You Ilma, and ABDUL HARIS ROSYIDI. "Kemampuan Siswa Dalam Menyelesaikan Soal PISA Kategori Formulate Pada Siswa Kelas VIII." MATHEdunesa 8.2 (2019): 400-407. https://doi.org/10.26740/mathedunesa.v8n2.p400-407 
9. Hala, Y., S. Saenab, and S. Kasim. "Pengembangan perangkat pembelajaran berbasis pendekatan saintifik bagi siswa sekolah menengah pertama." Journal of EST 1.3 (2015): 85-96.  Diakses darihttp://www.ojs.
10. Jaya, S., and A. Arnyana. "Pengembangan Perangkat Pembelajaran Fisika Bemuatan Pendidikan Karakter dengan Setting Guided Inquiry untuk Meningkatkan Karakter dan Hasil Belajar Siswa SMP." Jurnal universitas Yogyakarta 4.4 (2017): 49-57.
11. Octaviyani, I., Kusumah, Y. S., & Hasanah. "24569-53017-1-Sm." Journal on Mathematics Education Research, vol. 1, no. 1, (2020), pp. 10–14.
12. Susanta, Agus, Hari Sumardi, and Zulkardi Zulkardi. "Development of e-module using Bengkulu contexts to improve literacy skills of junior high school students." Jurnal Pendidikan Matematika 16.2 (2022): 171-186. https://ejournal.unsri.ac.id/index.php/jpm/article/view/17698 
13. Arsyad, Nurdin. "Model pembelajaran menumbuhkembangkan kemampuan metakognitif." Makassar: Pustaka Refleksi (2016).
14. Akker, Jan, et al., eds. Design approaches and tools in education and training. Springer Netherlands, 1999. https://link.springer.com/book/10.1007/978-94-011-4255-7 
15. Hendryadi, Hendryadi. "Validitas isi: tahap awal pengembangan kuesioner." Jurnal Riset Manajemen dan Bisnis 2.2 (2017): 259334. https://doi.org/10.36226/jrmb.v2i2.47
16. Mustami, Muhammad Khalifah. "Validitas, kepraktisan, dan efektivitas perangkat pembelajaran biologi integrasi spiritual islam melalui pendekatan saintifik." Al-Qalam 23.1 (2017): 70-77.  https://doi.org/10.31969/alq.v23i1.392
17. Aristin, Nevy Farista, et al. "Development Of Flipped Classroom Learning Videos as a Source of Independent Knowledge Exploration." JPG (Jurnal Pendidikan Geografi) 11.1. https://doi.org/10.24203/ajas.v9i6.6804
18. Mustofa, Ali, and Imas Cintamulya. "Pengembangan Handout Materi Biologi SMP Berbasis Pendekatan Konsep pada Sistem dalam Kehidupan Manusia." Proceeding Biology Education Conference: Biology, Science, Enviromental, and Learning. Vol. 14. No. 1. 2017. https://jurnal.uns.ac.id/prosbi/article/view/21118 
19. Riefani, Maulana Khalid. "Validitas dan kepraktisan panduan lapangan “keragaman burung” di kawasan pantai Desa Sungai Bakau." Jurnal Vidya Karya 34.2 (2019): 193-204. http://download.garuda.kemdikbud.go.id/article.php?article=1471135&val=9363&title=VALIDITAS%20DAN%20KEPRAKTISAN%20PANDUAN%20LAPANGAN%20KERAGAMAN%20BURUNG%20DI%20KAWASAN%20PANTAI%20DESA%20SUNGAI%20BAKAU 
20. Juliantri, Luqman Azhar, Totok Sumaryanto Florentinus, and Hari Wibawanto. "Pengembangan e-Rapor Kurikulum 2013 Berbasis Web di SMK Negeri 1 Slawi." Innovative Journal of Curriculum and Educational Technology 6.1 (2017): 11-16. https://doi.org/10.15294/ijcet.v6i1.15571 
21. Uno, Hamzah B. "Teori motivasi dan pengukurannya." Jakarta: Bumi Aksara (2008): 11-54.
22. Sumirattana, Sunisa, Aumporn Makanong, and Siriporn Thipkong. "Using realistic mathematics education and the DAPIC problem-solving process to enhance secondary school students' mathematical literacy." Kasetsart Journal of Social Sciences 38.3 (2017): 307-315. https://doi.org/10.1016/J.KJSS.2016.06.001
23. Priyonggo, Hendi Widi, Wardono Wardono, and Tri Sri Noor Asih. "Penggunaan Modul Agito dalam Pembelajaran Matematika SMA/SMK untuk Meningkatkan Kemampuan Literasi Matematika." PRISMA, Prosiding Seminar Nasional Matematika. Vol. 2. 2019.