For those not used to the idea of 6-, 7- and 8-year-olds sitting quietly on a mat as they pay attention to an adult, the scene was striking.

The youngsters of Monocacy Valley Montessori Public Charter School's lower-elementary class were in a circle, fidgeting only a little as they watched their teacher, Ingrid Sherwood, slowly, silently assemble a puzzle map of Africa, almost caressing the edges of the pieces as she put them into place.

It was a textbook example of the hands-on Montessori method of education, and the school's principal, Bettejane Weiss, watched from the doorway with satisfaction. "We need them to be ready for this when they get to [age] 5," she whispered, referring to the school's approach. For her, it was a sign that the four-year-old school in Frederick -- the first charter school in the state and one of the few Maryland public schools dedicated solely to the Montessori educational philosophy -- is working in the classroom.

Not that anything else has been easy. Back in her office, behind a desk piled high with file folders and papers -- a sign on her desk noted that "A Cluttered Desk Is a Sign of Genius" -- Weiss said that the school has faced its share of challenges since its founding in 2001 and that this year is key to its future.

"They struggled that first year, partly because they didn't know how it will all work," Weiss, a veteran of the Montessori method, said of the school. She was a consultant to Monocacy Valley that first year and became principal the next year.

One of the more recent problems involves the school's new building, rented from neighboring First Baptist Church. Monocacy Valley's classes started two days later than the rest of the school system's because the charter school had to secure a permit to use the building. And though the new building is much larger than the school's previous one in Walkersville, Monocacy Valley no longer has a grassy playground, and students take recess on an asphalt parking lot.

But the biggest challenge is reconciling the century-old Montessori style of education -- which prizes individual initiative in students, allowing them a great degree of freedom in teaching themselves and training their senses -- with more-structured public school standards.

"We have complete autonomy within the walls of the school itself," Weiss said. "The lasso tightens a little bit outside the walls. No one's quite sure where a charter school fits."

Fifteen charter schools, including Monocacy Valley, have been approved since Gov. Robert L. Ehrlich Jr. (R) signed legislation in 2003 for their start-up, including 12 in Baltimore, and two that opened this fall in Anne Arundel: Chesapeake Science Point in Glen Burnie and KIPP Harbor Academy in Annapolis. Four others -- two in Harford County and one each in Prince George's and St. Mary's counties -- have been approved but have not opened.

The principle of charter schools is to give parents who cannot afford private school the opportunity to have their children learn in a different educational environment. Monocacy Valley, however, is still responsible for meeting Maryland's standardized testing requirements and ensuring that all its teachers have a state teaching certificate.

The school's four-year charter requires Monocacy Valley to score at or above the county's average on the Maryland School Assessments to continue to receive state funding. But because Frederick is among the top-performing counties on that test, and because the Montessori method does not focus specifically on subjects that will be on the School Assessments, meeting the testing requirement is difficult -- and not meeting it poses the biggest threat to the 235-student school.

The school has scored below the county average. For example, 20.9 percent of the county's third-graders showed nothing beyond a basic aptitude for reading; but at Monocacy Valley, that figure was 30 percent. The gap was larger in math, with 18.4 percent of the county's third-graders being only basic performers, compared with 40 percent at Monocacy Valley.

The school has improved steadily on the tests, and the school's charter was renewed for another four years. Weiss, however, said she was worried that the charter could be revoked anyway if the school failed to meet the average this year. She said she has hired a specialist to help students with math.

"My responsibility as educational leader is to make sure that everything we do preserves the Montessori-ness of the education," Weiss said. "They still have to take that blankety-blank test in March. We're always mindful of the fact that that's part of our legal responsibility."

She also must hire teachers who have Maryland and Montessori teaching certifications. Because nearly all Montessori schools are private schools, there are few Montessori-trained teachers who have a public school certificate as well. Weiss said Monocacy Valley wanted to open a fourth class at the elementary level but could not find a dual-certified teacher, so the school had to put 92 children in three classes.

Weiss, however, said she tries not to put too much stock in standardized tests, instead emphasizing what happens in class.

In Penelope Fletcher's group -- she handles students ages 3 through 6 -- students wandered through the classroom: painting, reading, writing, tracing shapes and eating snacks, apparently as their spirit moved them. Contrary to what might be expected, the result was not pandemonium. Students interrupted Fletcher quietly, putting a hand on her shoulder or hip when they wanted her attention.

Jacob Reese had some trouble with that, standing next to Fletcher. Taking Jacob's hand, she guided him through putting on a paint smock until he was able to do it himself.

"That's it," she said slowly. "You have a very powerful mind when you focus."

Venus Elliott's upper-elementary students read at Monocacy Valley Montessori school. Joel Tate works out a math problem in his kindergarten class at Monocacy Valley, which encourages self-education.