Organization for Economic Co-operation and Development [OECD] (2016) released the results of PISA 2015 and reported that the students’ performance in Mathematics of Singapore and Indonesia had significant differences. There is a strong relationship between the textbook used and the mathematics performance of the students. If textbooks differ, students will get different opportunity to learn and the opportunity to learn influences students’ achievement (performance).
Material and methods:
Material : Singaporean and Indonesian Mathematics Textbooks
Methods: Qualitative study regarding horizontal and vertical analysis
This study found Singaporean textbooks put more emphasis on all the concepts of trigonometry on right-triangle and further trigonometry (sine/cosine rules) while Indonesian textbook provided more discussion on angle and its concepts, trigonometry on right-triangle, and graph function of trigonometry (which is a lot more difficult than sine/cosine rules. In addition, Singaporean textbook provided more mathematical questions requiring higher cognitive demand levels while Indonesian textbook provided more questions requiring lower levels.
The difference of textbooks design (mathematics topics and cognitive demand level) is a factor which influences student’s mathematics performance in Singapore and Indonesia