Secondary schools are the first institutions in Singapore to have implemented the “Overall Grade” grading system for academic subjects. Since the 2000s, the education system allows more capable Normal (Academic) stream students to participate in the O Levels examination for Mother Tongue and Mathematics (Elementary) a year instead of taking the N Levels equivalents. This has resulted with a quasi-O Levels grading system used for such students, although their N Levels subjects are graded along the Overall Grade grading system, thus in their result slip, some subjects will be graded along the Overall Grade, and some with the O Levels grading system.