ANALYSIS OF MATHEMATICS PROBLEMS IN THE 2013 CURRICULUM AND CAMBRIDGE CURRICULUM MATHEMATICS TEXTBOOKS

Several factors influence the success of learning; one of them is the quality of textbooks. Textbooks have a pivotal role in learning, namely, representing the teacher's explanation in front of the class. Curricula have continuously changed because they are far from the expectations. In Indonesia, many schools have implemented an international curriculum to improve school quality. One of the curricula used is the Cambridge curriculum. This study analyzed the types of problems in the Cambridge and 2013 curriculum mathematics textbooks, especially on quadratic equations. This research utilized a six-dimensional analysis method which consists of mathematical activities, complexity level, answer form, contextual features, response types, and mathematical features. Furthermore, the data collection technique was carried out by analyzing and describing the types of questions in the 2013 curriculum and the Cambridge curriculum mathematics textbooks. The analysis focused on the quadratic equation topic in the 2013 curriculum and the Cambridge curriculum mathematics textbooks. The results shows that there is no difference between the types of problems in the 2013 curriculum and the Cambridge curriculum mathematics textbooks for quadratic equation topics. The framework of this study could be a reference for further research and used by mathematics textbook writers to create m ore diverse types of questions. ARTICLE INFORMATION


INTRODUCTION
A system improvement could increase the quality of education. In Indonesia, remodeling textbooks to make them more appropriate and meet the applicable standards is one way to upgrade the education quality. Furthermore, Lessani, Yunus, Tarmiz, and Mahmud (2014) stated that students' knowledge and competence should be compared to other students from different countries to evaluate their performance and improve their achievement in science and mathematics at various levels of education. On the other hand, Mailizar, Alafaleq, & Fan (2014) revealed that to improve the quality of student learning in any education system, the government has to pay attention to the curriculum.
The curriculum is the central part of the system and plays a pivotal role in determining how students learn and are taught in school. It is the most fundamental structure for educational experiences. It is a kind of underlying "skeleton" that gives characteristic shape and direction to instruction in educational systems worldwide (Houang & Schmidt, 2008). The curriculum is defined as a statement, and students are expected to know and could do it (Levin, Connelly, & Lundgren, 2008). Richards (2001) claimed that the curriculum includes educational planning based on several processes that result in the development, implementation, and evaluation of language development.
The curriculum is also essential in Indonesia, which adopts a centralized education system. Thus, the 2013 curriculum revised is a solution to improve the deficiency of the previous 2013 curriculum. Furthermore, the educational goals will never be achieved appropriately if the curriculum is not equipped with qualified textbooks (Pramesti, 2017). A textbook can have a prominent position and role in implementing a mathematics curriculum (Johansson, 2003). A textbook is organized intentionally, and consequently, its content and structure are essential for promoting a specific vision of a curriculum (Okeeffe, 2013). The textbook has been identified as one of the factors that influence students' learning outcomes. Sunday (2014) claimed that textbooks had been emphasized to be the most critical media in the mathematics teaching and learning process.
Textbook as teaching media is unique because it has specific characteristics. The textbook receives attention from the international research community on mathematics education during the last few decades (Lianghuo Fan, 2011). The mathematics textbook is the leading media on which the teachers lay their teaching (Gene, Zacharos, Lavidas, & Koustourakis, 2018). It has been noted that the use of different mathematics textbooks by teachers leads to the adoption of different teaching strategies (L Fan & Kaeley, 1998).
In mathematics, content-specific literacy skills of students are needed since there are particular properties of mathematical texts. The symbolic language is a property of mathematics that needs literacy skills (Österholm, 2006). In this regard, the quality of the problems in the textbook must be considered. Problems are often designed to reveal facts that students know (or do not know), as well as the techniques that students are good at (or not mastered) and how to use them in certain situations (Brändström, 2005). Lai (2011) claimed that books provide the core elements of the subject and have to develop students' critical and creative thinking. Other research focused on particular mathematics topics, for example, the concept of proportion (Dole & Shield, 2008) and the concept of function (Mesa, 2004). Lianghuo Fan, Mailizar, Alafaleq, and Wang (2018) also presented a comparative analysis of textbook content, focusing on how geometric proofs are conveyed in secondary school mathematics textbooks in China, Indonesia, and Saudi Arabia. This comparative analysis considered three views: time to introduce evidence in the curriculum, distribution of evidence in textbooks, and the type of evidence introduced to students. Textbooks in China have the highest percentage of geometric content and pay the most attention to the topic of geometric proof itself.
Previous researchers have also conducted problem analysis of mathematics textbooks in Indonesia from the 1994 curriculum to the 2013 curriculum (2017 revision). Based on the study results, the questions in Indonesian textbooks generally have no significant changes even though the curriculum has changed from 1994 to 2017. The types of questions presented in mathematics textbooks in Indonesia still use various arithmetic operations, applying direct knowledge or basic skills without any daily life context. The existing questions are also the closed answer types; the questions only require direct answers without reason and a single procedure (Raditya, Iskandar, & Suwarno, 2020). Furthermore, Purnomo (2015) stated that the 2013 curriculum mathematics textbook's questioning aspects are challenging to implement because students do not understand the questions and are not confident to answer. The questions in the teacher handbook are also too complicated, so the teacher has to look for other references. Thus, the current research was conducted to describe the comparison between problems provided in the 2013 curriculum mathematics textbooks in Indonesia and the Cambridge curriculum mathematics textbook, which is applied in more than 160 countries.

METHOD
This research is a descriptive analysis. The subjects in this study were quadratic equations topics in BSE mathematics textbooks of the 2013 curriculum (2014 revised edition) and Cambridge curriculum. This research method utilized the collection of problems, sample problems, and practice problems from the mathematics textbooks used. The framework in this study was a modification of the framework developed by Gracin (2018) and Li (2000), namely 6-dimensional analysis; mathematical activities, complexity level, answer form, contextual features, response types, and mathematical features for analyzing problems in mathematics textbooks in Indonesia. Then, the researcher classified and converted the problems in the mathematics textbook based on the framework into a coding system. The implemented framework is presented in Table 1.

RESULT AND DISCUSSION
The study results indicated that, in general, there is no balance between the types of  Table 2.  There is no problem in the Cambridge curriculum mathematics textbook related to providing an argument or logical reason (A4) sub-dimension. The comparison of dimension A could also be seen in Figure 1.  of the C3 problems in the Cambridge curriculum. The comparison of dimension C could also be seen in Figure 3.   Mathematical problem dimension (dimension F) with a single process (F1) problems in the Cambridge curriculum mathematics textbook has a higher percentage than layered process (F2) problems which equal 87.13%. In contrast to the 2013 curriculum mathematics textbook, the layered process (F2) problems are more significant than the single process (F1), 73.85%.
The comparison of dimension F could also be seen in Figure 6. In 2013 curriculum textbooks, it is dominated by representing or modeling problems, while in the Cambridge curriculum textbooks, it is dominated by problems of counting or using various counting operations. Problems in the 2013 curriculum mathematics textbooks are dominated by making connections problems, whereas the Cambridge curriculum is dominated by applying reflective knowledge problems. Furthermore, the Cambridge curriculum mathematics textbook's single process problems have a higher percentage, which is inversely proportional to the 2013 curriculum mathematics textbook. Then, the percentage of layered process problems is more significant than the single process.

CONCLUSION
The 2013 curriculum applies a modern principle approach that refers to a scientific method in the Cambridge curriculum. The difference between the 2013 curriculum and the Cambridge curriculum is related to the learning system. The Cambridge curriculum is more focused on students' exciting subjects. Meanwhile, the national curriculum (one of them is the 2013 curriculum) equalizes all students' subjects.