Many schools in Asia uses the "Mastery Approach" to teaching math. The rationale behind this approach is simple; since math is a subject where one topic builds upon another, a student should not go on to a higher topic until he/she has mastered the lower level topic. A simple analogy is teaching someone to run before he/she has learned how to walk. The end result is the person will stumble and fall.
The following link describes in detail the Mastery Approach to teaching.
https://www.yahoo.com/finance/news/top-performing-asian-countries-mastery-171300479.html
At Mathnasium, we use a similar philosophy in helping our students to make math make sense. We first give our students a comprehensive assessment. Based on the assessment, we then give our students exercises focusing only in those topics we have identified as weak areas. Students work with trained Mathnasium instructors, using our proprietary ciriculum and teaching method, to master these topics. At the end of each topical exercise is a "mastery check", where students work independently to demonstrate mastery of the topic taught. Until a student has mastered a topic, we will re-visit that topic before moving on to other topics.
