English textbooks are the most pivotal learning materials in the EFL context. However, in Vietnam, English textbooks for general education are randomized by schools, which arouses a problem of whether they are equivalent for students to gain the same proficiency. This study attempts to report the differences in lexical demands and features,…

Coordinate geometry is an important part of mathematics. It helps students develop thinking, logic, and problem-solving skills. This study was conducted to test the effectiveness of the CORE learning model in promoting students' mathematical problem-solving skills when they learn the method of coordinates in a plane. Consequently, this study used…

In EFL countries where English is rarely practiced outside the classroom, textbooks have become the major input source for learners. Particularly in Vietnam, multiple textbook series are available simultaneously for the same grade. Thus, it is important to examine if their vocabulary is appropriate and of similar difficulty. This study aims to…