NEW YORK CITY —  Mayor Bill de Blasio struck a triumphant tone Monday morning when he declared almost 75 percent of the city’s 981,000 public, non-charter, schools students had decided to enroll in blended learning, which will see kids return to classrooms between 2 and 3 days a week. 

“Our kids have been yearning to reconnect with school, with their friends, with so many teachers and mentors they depend on,” de Blasio said. “We’re going to be ready to serve our kids in September.” 

But about 586,000 students (or about 80 percent of the 736,000 kids signed up for blended learning) were enrolled automatically because their parents did not submit a survey, and retain the right to switch to remote, DOE spokesperson Miranda Barbot confirmed.

As many as 264,000 of New York City public school students opted not to return to classrooms this fall and only 131,000 parents have openly declared their intention to send kids back to school, officials said. 

Several parents, among them a PTA leader and DOE teacher, told NY1 they did not fill out the survey because they were seriously concerned about their children’s health and safety and wanted to keep their options open. 

The DOE teacher and mom of three, who asked not to be named, said she, her husband and handful of fellow teachers did not fill out the survey, even though they intend to choose remote learning, because they need to see their schools' schedules first. 

"I imagine many families are in a similar predicament to mine," the teacher said. "How can parents arrange childcare if they do not know the days their children will be in school?” 

Jessamyn Lee, PTA president at P.S. 84 Jose De Diego in Williamsburg, was outraged at what she called de Blasio’s misleading numbers, pointing out those without digital access could not fill out the form. 

"It doesn’t capture who has opted in,” Lee said. "It captures who has opted out.” 

Lee completed the survey but may still opt for remote learning — even though her daughter relies on in-person special education services — after she made a grim discovery Monday morning’s newspapers. 

Twenty fans meant to send fresh air flowing through her kids’ school are broken, according to the Daily News.

"I attended a meeting last week and the facility manager for Brooklyn North was on the call,” Lee said. “He assured us our buildings are ready.” 

When faced with concerns over ventilation, the mayor would not promise that 100 percent of classrooms would see ventilation upgrades but pledged that no unsafe classroom would reopen.

De Blasio’s Senior Health Advisor Dr. Jay Varma rushed to assure parents only safe classrooms would reopen and urged them not to underestimate the value of masks and open windows. 

 "Ventilation is one piece, an important piece, but not the only piece,” Varma said. "We feel very confident at this moment ... that New York has control of this epidemic.” 

But concerns remain as parents, students and teachers await the unique plans New York City’s 18,000 schools must soon submit, and which were not included in the DOE’s 109-page citywide reopening plan.

"This is one step in the process of figuring out if schools reopen how to do it safely,” said Michael Mulgrew, president of the United Federation of Teachers. "Many questions about safety and about blended learning are still unanswered.” 

About 66,000 teachers, or 85 percent of teachers, will return to classrooms while 15 percent have asked to work entirely from home, according to DOE Chancellor Richard Carranza. 

De Blasio admitted Monday yet another challenge faces New York City’s public schools. 

Schools could see staff cuts amid an economic upheaval spurred by New York's stay-at-home order and lack of federal funding de Blasio has said could force him to slash 22,000 city workers' jobs, the mayor warned.

 "Our goal here is to keep all our city employees in place," de Blasio said. "We either need help from Washington or Albany to avert having to lay off our teachers or other employees."