Are the Mathematics Textbooks for Eighth-Grade Meet the Trends in International Mathematics and Science Study ( TIMSS ) 2019 Mathematics Framework ?

This study aims to determine the suitability of mathematics textbooks for eighth-grade with Trends in International Mathematics and Science Study (TIMSS) 2019 Mathematics Framework. This research uses a qualitative research method with a descriptive approach and content analysis techniques. The data of this research are the eighth-grade mathematics textbook. In the textbook analysis, the researcher used three textbooks, namely Penerbit Erlangga, Yudhistira, and the Ministry of Education and Culture (Kemendikbud). The analysis carried out was the analysis of the content domain and knowledge domain based on the TIMSS 2019 Mathematics Framework. The content domain contains numbers, algebra, geometry, and data, and probability. While the knowledge domain contains aspects of understanding, application, and reasoning. In the Penerbit Erlangga book, there are only 2 out of 4 pieces of content contained in TIMSS, while the cognitive domain is 2 out of 3 aspects. Yudhistira book 2 of 4 content contained in TIMSS, while the cognitive domain is 1 of 3 aspects. Kemendikbud’s book is 1 of 4 content domains in TIMSS, while the cognitive domain is 1 of 3 aspects. Therefore the three eighth-grade mathematics textbooks as a whole are still not suitable for the TIMSS 2019 Mathematics Framework.


INTRODUCTION
General education and specifically science education consider that mathematics education is an important component. It is relevant to compare the other countries' different levels of education which may know student's evaluation and to develop their policies to improve their achievements in science and mathematics (Lessani, Yunus, Tarmiz, & Mahmud, 2014). Trends in International Mathematics and Science Study (TIMSS) is one of the international evaluation that conducting it.
TIMSS is an international assessment of mathematics and science at the fourth and eighth grades that well established as a valuable resource for monitoring educational effectiveness in their education system related to the student's achievement in science and mathematics. TIMSS mathematics assessment framework has two domains, content domains, and cognitive domains.
Indonesia has participated in TIMSS's international study regularly every four years from 1999, 2003, 2007, 2011, and 2015. Indonesian was ranked 32 nd of 38 countries that participated in that study in 1999, 37 th from 46 countries that participated in that study in 2003, 35 th from 49 countries that participated in that study in 2007, 39 th from 43 countries that participated in that study in 2011, and 44 th from 49 countries that participated in that study on 2015 (Wahyuningrum, 2017). The results show that Indonesian students' achievements are low ranked.
Textbooks are a primary need in learning and one of media learning which able to increase the effectiveness of learning (Macintyre & Hamilton, 2010;Hendrice, Valeria, Kurnila, & Jundu, 2018). Learning can be increased by textbooks which have good quality. We should pick the textbook carefully and we should use it maximally. A textbook is a printed knowledge that plays a significant role in shaping teachers and students (Okeeffe, 2016;Padmawati, 2017). Students can learn the subjects anywhere, not only in school and without teachers teaching them. The intended curriculum and the implemented curriculum are bridged by textbooks, it helps teachers for planning lessons in the class (Jelić & Đokić, 2017;Reyhani & Izadi, 2018). TIMSS has a result that when teachers select their teaching method they use mathematics textbooks as their main resource especially for tasks and practice exercises (Gracin, 2018;Yang, 2017).
Badan Standar Nasional Indonesia (BSNP) team who formed by the minister has assessed the textbooks starting from content, language, presentation, and graphics (Padmawati, 2017). The government has provided textbooks that suitable for the current curriculum namely the scientific curriculum with the hope that the students can be more critical in thinking so Indonesia will have better quality in education. However, TIMSS hasn't assessed the textbooks, so the textbooks always change according to the current curriculum. find out the suitability of the textbooks and also we may know which textbook is better.

RESULTS AND DISCUSSION
Penerbit Erlangga textbook has 199 pages in its 1 st semester and 231 pages in the 2 nd semester, so the Penerbit Erlangga textbook has 450 pages in total for one year. Yudhistira textbook has 245 pages in a year. For the Kemendikbud textbook, it has 252 pages in the 1 st semester and 321 pages in the 2 nd semester, so the total is 573 pages in a year.

Content Domains
The three mathematics textbooks had some contents that suitable for to TIMSS 2019 Mathematics Framework, not all of the contents. The results of the analyzed mathematics textbook are presented in Table 1. From that analysis, geometry content dominates the three textbooks which were above 50% of the target percentage. Muawan (2016) said that the content of mathematics textbooks was dominated by geometry contents. The second content was number, the third was algebra, and the last was data and probability content. The mathematics textbook which had the highest percentage for number content was Penerbit Erlangga also for the geometry and data and probability content.
While the mathematics textbook which had the highest percentage for algebra content was Yudhistira.

Cognitive Domains
Cognitive domains contain knowing aspects, applying aspects, and reasoning aspects. There were some aspects in mathematics textbooks that were not suitable to the cognitive domains of TIMSS 2019 Mathematics Textbook's target percentage. Table 2 presented the result of cognitive domains and the target percentage of cognitive domains. From the three aspects, applying aspects had two suitable mathematics textbooks. As Muawan (2016) found that applying aspects had the highest percentage than knowing and reasoning aspects. The mathematics textbook which had the highest percentage for knowing aspects is the Yudhistira textbook. Meanwhile, the highest percentage for applying aspects went to the Erlangga textbook, and the highest percentage for reasoning aspects was the Erlangga textbook too. Besides, the teachers should give the students examples or exercises from other resources to make the students more skilled in knowing, applying, and reasoning aspects. Through analysis and comparison of the textbooks based on TIMSS content can provide writers and curriculum designers to improve the curriculum to facilitate higher achievements in mathematics learning.