25 November 2025
A widespread topic of discussion surrounding O Level Mathematics is whether a bell curve determines the final grade. But is this actually true, or is there more to the grading system than what the majority think?
Bell curve grading assigns grades relative to the performance of an entire cohort, based on a normal distribution with a predetermined average. It is named after the bell-shaped distribution of grades. The grading system aims to adjust for inconsistencies and accommodate different grading styles among teachers, ensuring the exam reflects student grades based on their relative achievement.
While it helps to promote healthy competition among students, it may be considered unfair when students’ grades are lowered to match predetermined bell curve calculations. Various approaches aim to ensure a fairer grading scheme that still accounts for the multitude of learning capabilities among students, and the Singapore Examinations and Assessment Board (SEAB) continually refines examination standards each year.
The bell curve is a frequent point of discussion during every examination cycle. In 2023, SEAB clarified that all national examinations, including the O Levels, are not graded using a bell curve. Instead, they follow a “standards-referenced” approach in assessing a “candidate’s level of mastery in a subject”. However, it is common for test scores to follow a bell curve distribution, as it reflects the varied levels of understanding among students.
SEAB’s clarification indicates that the national grading format does not “force fit” students to a preset bell curve, as each examination is carefully designed to “syllabus objectives and learning outcomes” that cater to “students of different abilities”. The bell curve is an incidental occurrence that merely reflects the natural variation of understanding across subjects.
Many educational institutions use the bell curve as a moderation tool to maintain fairness in grading. Grades are assigned based on a student’s level of mastery in a subject, ranging from A1 (highest) to F9 (lowest). If more candidates demonstrate higher-quality work and a stronger understanding each year, a higher percentage of them will receive better grades.
Grade moderation helps to protect students from grade deflation or inflation. Rather than comparing a student’s performance to their peers, grades are aligned with the yearly syllabus to reflect how well each student meets the set standards. This ensures fairness and consistency when grading student performance.
In the context of O Level Mathematics, it reflects the student’s mathematical foundations and how well they can apply them to solve various questions.
An important thing to note is that the bell curve should not be seen as a barrier to scoring well. While it does increase competitiveness among students, it can also easily drain a student’s motivation to do their best in any examination, including the mathematics paper. This can be detrimental to a student’s overall performance and even self-esteem, especially when they need more revision and personalised guidance to overcome their worries and doubts.
As such, an effective way for students to overcome their fear is by collaborating with their peers. While healthy competition is good, too much of it can be discouraging, making it more important to find ways to work and learn from one another. Seeking guidance through tuition classes can also be beneficial in supporting their understanding.
Study groups are an excellent and engaging way for students to learn from one another, with opportunities to share insights on various mathematics concepts, questions, and formulas. Peers may understand certain mathematical concepts and questions more clearly, providing guidance that is concise and easily understood. This also fosters a spirit of collaboration that can greatly motivate each member of the study group, giving everyone a boost of confidence by celebrating their successes, no matter how small.
Tuition sessions are led by tutors who take a more personalised approach to teaching mathematical concepts and providing helpful revision. Tutors can take the time to adjust their teaching style based on each student’s individual needs, allowing them to grasp concepts more easily. Whether through one-on-one sessions or carefully curated teaching plans, tuition classes can strengthen a student’s mathematical foundation, ensuring a clearer understanding of the subject.
For students preparing for the O Level Mathematics papers, Matrix Math offers personalised classes that give students a helpful advantage to organise and solidify their foundations. Contact us today to learn more about how we can empower your child to do their very best!
