Education advocates hope this black and white billboard in Brooklyn will catch the eye of parents in the borough's large Orthodox Jewish community, where more than 84,000 students attend religious schools, many of which do not meet legal minimum requirements for instruction in English, science and math. View Full Caption DNAinfo/Sonja Sharp

GOWANUS — Education advocates fed up with a lack of English, math and science in some Jewish parochial schools have taken their frustration to the street — or, more accurately, to a huge billboard overhanging the BQE.

Activists from New York's Orthodox Jewish community say the Department of Education is failing to enforce legal minimum standards for basic education in some yeshivas.

The activists said that when they tried to buy ads in the city's prominent Yiddish-language newspapers to bring attention to the shortfall in instruction, they were refused space. So they bought the billboard.

"It's your mitzvah," their message read on Prospect Avenue Tuesday. "It's the law."

A DNAinfo New York investigation earlier this year uncovered huge scholastic gaps at many of Brooklyn's most prominent yeshivas — schools that serve more than 84,000 students, a third as many as attend the borough's public schools.

Educators continue to flout that law, and officials continue to ignore it, the investigation found.

The billboard includes a quote in Hebrew from Talmud, which says a person must teach his son a trade, said activist Naftuli Moster, whose organization YAFFED (Young Advocates for Fair Education) has spent more than a year lobbying city and state education officials to enforce "equivalency of instruction" rules in the city's crowded Jewish schools.

"Obviously, nowadays yeshivas should take on that role as messengers of the parents," Moster said.

At Williamsburg's enormous United Talmudical Academy, male students receive fewer than six hours of general instruction a week for four years, while Crown Heights' Oholei Torah doesn't teach English or math at all, the investigation found.

"Our strategy has always been to get people from within the community to speak up and demand a change in the current education system, where 14-year-olds spend 14 hours a day without learning a single word of English, math, science, history or geography," Moster said.

"All are subjects that schools are required to provide by law, and the government is required to ensure that schools do."

Instead, the city DOE has ignored schools under its supervision that graduate students without Regents diplomas — many of them functionally illiterate in English, DNAinfo New York found.

The DOE did not immediately return calls for comment.

In parts of Borough Park and Williamsburg, it's common to find young men who were born in New York, educated all their lives in Brooklyn and yet struggle to hold a simple conversation in English.

"Just a few weeks ago I tried putting ads in a few Jewish newspapers. They were rejected," Moster said.

"It had some different wording, more text. It said, 'Your son deserves better.'"