A North Atlanta High School student is one of just six students in the world to earn a perfect score on a 2017 Advanced Placement calculus exam.

The College Board, which administers AP tests, announced this week that Richard Hill, a North Atlanta senior, got every question right on the Calculus AB exam he took in May as a junior. A total of 317,663 students took that test, and he was among only six to ace the timed, paper-and-pencil exam that includes 45 multiple choice questions and six “free response” questions.

"It was very shocking to me. I didn't even consider it a possibility," said Hill, who also achieved a perfect score of 36 on the ACT and is interested in studying math, physics, and engineering in college. He has applied to University of Georgia and Georgia Tech, as well as the University of Alabama and several schools in California and in the northeast.

He credits his North Atlanta math teacher, David Ehrman, for in-depth instruction and a series of YouTube videos called "Essence of Calculus" for preparing him to take the test. Gaining an intuitive understanding of how calculus works helped him correctly answer even the most difficult problems: "If you understand all the calculus you can fill in all the knowledge," he said.