Made by a Korean college admissions consultant. Most students look at a mistake once and move on — then miss the same question on the test. This coil-bound notebook turns every mistake into a card you meet five more times: 1, 3, 7, 14 and 30 days later. Each time, you cover the answer and solve it again before checking. Five correct reviews in a row and the card "graduates." Inside (128 pages, A5, lies flat): - 100 numbered Mistake Cards: problem space, why-I-missed-it tags (careless error, concept gap, misread the question, ran out of time), what went wrong / key idea boxes, and a 5-step O/X review grid with a retry row - Review Schedule chart: find your start day, read off all five review days - Card Index to track every card until it graduates - 12 undated Weekly Review pages (84 days): new cards and cards due, day by day - Monthly mistake-reason tally, test score log and dot-grid notes Designed by Sehyun, a Korean college admissions consultant. While preparing for Korea's national college entrance exam, she reviewed her math mistakes on this exact schedule and raised her math score by 22 points in three months. That's her personal experience, not a promise — results depend on your starting point and study time. Works for math and any subject where you practice problems. A study planner for high school and college students.