The objectives of Education during Century 21st was to focus on students to be able to solve the problems,
have critical thinking, and higher-order thinking which were necessary skills for students in news and information
period (Farrington and Small, 2008). Therefore, to develop body of knowledge as well as students’ Mathematics
ability were major objectives since Mathematics could help to develop problem solving ability, and logical
reasoning as well as foundation of other sciences, and indicator of success in Thai education system for preparing
the quality people in the future. So, the educational management in Thailand began to change curriculum in
Mathematics learning substance for students to obtain Mathematics knowledge, skill, and desirable characteristic
(Office of Academic and Educational Standard, 2008a) relevant to usage enhancing the learning during the 21st
Century. However, Thailand was alert in Educational Reform by modifying curriculum to included the same
standard throughout the country, and considered the findings of educational reform through output and outcome
occurred with students in Mathematics Learning Substance by giving an importance to the measurement and
evaluation in both of national and international levels such as the Ordinary National Education (O-NET), evaluation
outcome of TIMSS as well as PISA etc