MISHAWAKA, Ind. (WSBT) — There’s smart and then there is perfection.

Penn High School can say one of its students is perfect, as the only one in the world to receive a perfect score on the AP Calculus Exam.

AP exams are designed to be challenging and prepare students for college level courses.

While math may be a tough subject for many, it certainly wasn’t for Felix Zhang, a junior at Penn.

Math has always come easy for Zhang.

His teacher, Denise White, says she can always count on him to get the answers correct.

She says he’s quiet but a very hard worker.

And after seeing his exam scores from last year, he deserves the spotlight.

“It was pretty surprising because going into the test I wasn’t really expecting anything that much. Obviously, I wanted to do well on it, and I prepared a lot, but I never actually thought about getting a perfect score before,” said Zhang.

It’s not just that he was perfect, but out of 270-thousand students worldwide he was the only one to earn every point possible on the AP Calculus AB Exam.

“I was not surprised that Felix accomplished this. The surprising part was that he was the only one in the world. His reaction was so humbling,” said Denise White, Penn mathematics teacher.

Zhang says he remembered walking out after the test feeling pretty confident.

“A few of them maybe not 100% sure on, but I wouldn’t say I guessed on any of them,” said Zhang.

White says there’s no luck in what he accomplished.

“AP is concerned with not only knowing how to do the problem but also to be able to explain it. That is one of the things that Felix probably work the hardest on is to make sure the justification of his work, and that’s why I think it’s amazing that the perfect score came out,” said White.

Zhang credits his preparation, taking time to double check his work, and of course having both parents with doctorates in math teaching at colleges helps.

But a lot of credit needs to go to White as well.

As more than half her class last year received some of the highest scores on the exam.

“There’s a lot of strategies that teachers can put in place to help kids learn. but when you have kids scoring it at five you know the curriculum is intentional, it’s focus, the kids are engaged, and there’s a collaborative environment in the classroom that allows other kids to absorb the learning,” said Sean Galiher, Penn High School Principal

Zhang says he isn’t sure what he wants to do next but knows it will definitely use his math skills.

The only question he doesn’t know is if he can repeat his perfection on this year’s AP exam.