This study focuses on the discussion of the core mathematics curricula, including fractional and real Arithmetic, how to use the unknown number in math and certain questions as well as some mathematical concepts which are quite confusing to those students. The study shows that there is a huge gap in ability between students in mathematics. To those who have low ability in mathematics, it is quite a challenge to keep up with other students with average abilities. Therefore, this study put the most common mistakes that students made together as the reference to the teachers participating the remedial teaching, hoping to efficiently enhance students’ abilities as well as confidence in mathematics.