OSHKOSH, Wis. — Algebra is not the easiest subject for the average person to understand, but it’s even more difficult for a blind student.

Without seeing numbers, equations and mathematical formulas, blind students need a way to understand algebra and work through math problems.

That’s where a group of men in prison lend a hand. In a small room at the state prison in Oshkosh, 18 inmates help blind math students learn geometry and calculus, blind musicians memorize songs and blind travelers navigate with maps.

Earning 35 cents an hour and working seven hours a day Monday through Friday, inmates perform the painstaking work to unlock textbooks for blind and other vision-impaired students.

Dot by dot, letter by letter, number by number, John is transforming a first-year algebra textbook into Braille. “Every book you do is different. It’s a challenge. It keeps the mind sharp,” he said. Only inmates’ first names were allowed to be used in this story.

The prison began its Braille transcription program in 1997 at the suggestion of an inmate who had been a court reporter. Since then, 1,730 projects encompassing 10 million Braille pages have been completed, said Braille instructor Kurt Pamperin. Last year, 312 books with 750,000 pages were transcribed into Braille at the medium security prison.

Inmates, some of whom have blind family members, apply to work as transcribers. It takes nine to 12 months to earn Literary Braille Certification through the Library of Congress. Students can earn 12 credits from Fox Valley Technical College. Forty-seven inmates have graduated from the program, including a few who started a community-based Braille transcription service after their release.

“There’s a strong feeling of pride: I translated this book and somebody will read it,” said Clinton Bryant, education director at the Oshkosh Correctional Institution. “The guys speak about it with passion.”

Oshkosh Correctional Institution is one of 33 prisons in 26 states with Braille transcription programs. Turning textbooks, maps and music into Braille requires humans and, with little profit to be made, organizations that do this work tend to be nonprofits and prisons.

Don, an Oshkosh inmate, is among the few Braille transcribers who handle music scores and books. A musician who sang in choirs, Don earned the Literary Braille Certification and continued his studies to learn music transcription, which took two years.

He has transcribed music for students at the University o Wisconsin-Madison and UW-Oshkosh. One page of a full orchestral score can take him a day or more to transcribe.

“It’s kind of neat. I can help somebody learn this music and help a blind person have this connection,” he said.