At Crossway Community Montessori School, on a typical morning, adults greet little ones with handshakes. Children covered in aprons wipe down tables, wringing soapy yellow sponges. And students working with mathematical models move to the next learning activity when they choose — not when a teacher tells them.

Montgomery County is home to a nationally renowned education system, yet parents have been clamoring for a spot at Crossway, the county’s first and only charter school. It also is the county’s only school that provides a public Montessori education, which encourages students to learn independently in a flexible teaching environment while emphasizing development of practical skills.

The school appeals to parents such as Jennifer Nicholls because it offers the combination of a free Montessori education with Montgomery’s resources and brand.

“I like what my daughter is learning and who she is becoming as a person,” said Nicholls, whose 5-year-old attends the school. “Montgomery County is so superb at academics, but Montessori is so superb at skills kids need for life.”

Though the school recently wrapped up its inaugural year and looks forward to teaching kindergarten-aged children this fall, Crossway’s future is uncertain. School and county officials said the charter is struggling to develop a sustainable financial model.

Montessori education for students in the United States often starts at 3 years old or earlier. But in Montgomery — and many school systems around the country — a free and public education starts in kindergarten at about age 5. In the case of a public charter such as Crossway, public funding also begins in kindergarten.

As a result, the charter school needs to raise about $150,000 annually to continue programming for those younger than 5, Crossway Community chief executive Kathleen Guinan said. Crossway gets federal subsidies for low-income students and resources from Montgomery, but it isn’t enough.

The school has been holding cookouts, festivals and flower bulb sales to generate income. Students have even lugged bags of pennies to school in an effort to help. It’s all part of being a charter school and a “fledgling organization,” Guinan said.

“We’re looking to . . . different funding models, but we really have made the commitment to have a fully implemented Montessori curriculum,” Guinan said. “We really want what is best for children, and that is why we did this.”

President Obama has made early-childhood education a ­second-term priority. Early learning has been deeply rooted in the Montessori tradition since Italian physician Maria Montessori first developed the educational practice more than a century ago.

The Montessori classroom is different from those in traditional schools. At Crossway Community, a work cycle lasts about three hours. Teachers, referred to as “guides,” set parameters for student learning activities, but the students — who learn together in mixed-age classes — choose what to do and when to do it.

“When most people think of Montessori, they think it is a free-for-all,” Guinan said. “It’s not. It’s structured [and] ­student-centered.”

From counting beads to poring over a map of Africa to learning to tie one’s shoes, it all is designed to develop “the whole child,” socially, emotionally, physically and academically. Even snack time is part of the curriculum. Montessori students count out the number of cheese cubes and veggies they take from bowls to their plates.

Jane Meier wanted to send her daughter Ella to a Montessori school, but tuition didn’t fit into the family’s budget. Then came Crossway.

“Montgomery has great public schools . . . so it wasn’t a totally easy decision,” Meier said. But Meier said the self-directed class schedule has been a better fit for Ella, 5, who has a long attention span and felt rushed in a regular preschool class.

Nationally, interest in public Montessori schools is growing. In 2000, there were about 250 public Montessoris in the United States, said Keith Whitescarver, director of the National Center for Montessori in the Public Sector. There are now about 500.

Whitescarver said there is often tension between public school systems and entities looking to open Montessori schools as they hash out issues related to curriculum, funding and autonomy.

“One of the interesting things in Montgomery County is the close relationship between the district and the school,” Whitescarver said. “In some states, the charter is handed down from the state board of education and the school is plopped into the district. There isn’t really much interaction.”

In Montgomery, there has to be regular interaction, because Crossway is accountable to the public school system, said Lori-Christina Webb, executive director of the district’s office of teaching, learning and programs.

“We have a vested interest in ensuring all of our students are getting the best possible education,” she said. “We try to offer support and accountability and yet respect the autonomy of a charter. It is a delicate balance.”

The relationship between the school system and the charter school will become particularly important as Crossway begins teaching kindergarten-age students this fall and looks to develop sustainable funding. Crossway opened in August with about 70 students, and about 40 new children are expected for the coming year. The plan is for the school to eventually teach students through third grade.

Meier said she hopes the school will find stability so her daughter can stick with a Montessori education.

“I want them to be successful,” Meier said. “I don’t want to start this for my kids and not be able to keep it going.”