Two boys from a school in Manchester are among only four in the country to gain full marks in their further mathematics GCSE.
Raymond Ding, 16 and Jamie Horton, also aged 16, both went to Manchester Grammar School and say they were shocked by their achievements.
Raymond from Burnage, said: "I'm pretty happy. It's been a challenging year."
Jamie from Didsbury, said: "I can't believe it. I would never have expected that at all. It's pretty crazy."
Further mathematics is a new GCSE qualification, which is meant to be more challenging.