MUKILTEO — He is one of 10 students worldwide who received a perfect score. His teacher called him a crown jewel.

Joey Schafer, 16, is a junior at Kamiak High School. He took his first college-level Advanced Placement exam in computer science in May.

Test performance is rated on a scale of 1 to 5. Joey scored a 5. This is equivalent to an A.

Last week there was a letter from the College Board on his kitchen counter. His parents and younger sister waited while he read.

Not only did Joey score a 5, he also had a perfect score. This placed him in a select category comprised of only .02 percent of this year’s AP computer science test takers.

“I felt confident I passed, but I didn’t think I got a perfect score,” Joey said. “I didn’t know that this kind of letter existed.”

Nathan Binz, Joey’s computer science teacher, said his students on average score a 4 on the AP test.

“This is a once in a career type of thing. Not many teachers have this privilege of a student doing so well,” Binz said.

Joey started out in an introductory computer science course last year. He was a sophomore in a class of juniors and seniors.

“Joey is one of those kids who is always on task. He’s intelligent and on point,” Binz said. “He’s a dream student.”

After mastering the basics, Joey moved on to a coding language called JavaScript. He learned how to make a fraction calculator and a simplified version of a spreadsheet.

To celebrate birthdays in his family, Joey programmed digital birthday cards.

He also dabbled with graphing calculators.

He can program a calculator to spit out information about a specific number, such as its square root.

“You can be creative, but there’s still some logic to it,” Joey said. “There are right answers, but there are different steps you can take to get there.”

Following the AP exam, Binz introduced options for the class’ final project. Many pursued a research project on the history of computer science. Preparation for the AP test had done them in. They needed a break.

Joey decided to explore Unity, a more advanced coding language. He designed a two-dimensional endless runner game, similar to Temple Run.

The transition from JavaScript to Unity was “like saying go read the Odyssey in English, then go read it in ancient Greek,” the teen said.

It was difficult.

But Joey appreciates intricacy.

He scours code to find errors among parentheses, numbers and letters. He plays pieces written by classical pianists such as Felix Mendelssohn. And since fourth grade, he has practiced origami.

Joey even coordinated an origami club for middle schoolers. He meets with them weekly.

He feels fortunate Kamiak High School has computer science classes. Not many do.

Only 7 percent of Washington high schools offer AP computer science classes.

Binz took over Kamiak’s computer science program four years ago and made it his own. He had spent the 10 years prior teaching math.

Originally, the classes were lecture-heavy. Binz said many students struggled to grasp the material. They would go home and spend hours practicing.

Binz transformed the classroom into a “coach and his team” environment. Students spend the majority of class time working together on projects and asking questions.

Binz wants them to be curious, and successful.

Joey plans to attend college, possibly at the University of Washington. He hopes to study math, physics or computer science.

But for now, he is not worried about where he is headed. He is focused on the next line of code.

Caitlin Tompkins: 425-339-3192; ctompkins@heraldnet.com