Their results were unexpected as the 13-year-olds were known to be struggling with the subject. As children from single-parent families, both were too poor to afford private tuition.

Wei Shing also has dyslexia, which had caused him to consistently fail the subject. Zhi Wei, although a good student, had been falling behind in school, distraught that his mother was dying from brain cancer.

Read the full report in Tuesday's edition of The Straits Times.