The 3- and 4-year-olds were gone for the day when the 5's spread around the classroom after recess, picking puzzles and books to tackle alone while the teacher helped a boy count from one to 100 with crayon-sized sticks on the floor. The boy was at 36 and slowing when the sound of prayer trickled in from the atrium next door. School Director Robert Soley was with two students in a tiny corridor at a child-sized altar decorated with a cross and lighted candles.

Suddenly, a boy and girl ran in from the unsupervised classroom beyond the atrium and interrupted Soley's prayer with volleys of, "She pushed me," and "I said, 'I'm sorry.' "

Soley smiled as the tattling and guilty students asked what was going on in the atrium.

"Oh, we're just talking."

The Christian Family Montessori School in Mount Rainier, which was founded in 1981, offers a rare combination: reliance on the Montessori method and a Catholic education for its 70 students, ages 2 1/2 to 9. The school plans to add fourth, fifth and sixth grades next fall.

The mix makes CFMS one of only about 50 private schools in the country devoted to mixing Montessori and a religion-based education. School directors say it is the only of its kind in the Washington area. By throwing in cost-cutting techniques that allow a comparatively low annual tuition of $3,000 to $4,000, the school has become a model for Catholic parishes and organizations starting similar schools as far away as South Bend, Ind.

Maria Montessori's belief that a teacher inside all children motivates them to learn and discover dominates the way students are taught at the school.

Jill Hall, a primary education teacher of students ages 2 1/2 to 6, measures children's development by how motivated the students are to work.

"We know they are succeeding when they aren't in need of someone pushing them. The encouragement to meet challenges comes from inside them," she said.

Hall joined the school because she was attracted by its emphasis on religious teachings. She then trained to become a certified Montessori teacher, and has taught primary students there for several years. She brushed away the thought that she could make more money somewhere else.

"There are not many other places I could imagine teaching," she said.

Montessori education emphasizes order and the value of accomplishing work to children as young as 2 1/2. Students are taught to treat washing a table and folding towels, typical assignments at the school, as problems that must be solved through a series of concrete actions. Students learn the importance of clearing, rinsing, washing and drying the table, and appreciate the value of completing the task.

They also are encouraged to help run their classroom community and develop leadership skills and independence. Montessori classrooms do not often use textbooks or workbooks; their teachers instead look for firsthand experience and materials to teach classroom lessons. In recent years, many non-Montessori schools have incorporated some of the Montessori teaching methods.

When Judy Walsh-Mellett, assistant director at the school, recalled a recent visit from a group from New York asking how the school operated. She remembered asking, " 'Why did you come to us?' The woman said, 'You're the best.' It's funny, we never would think of ourselves that way."

The school instead thinks of itself as a community that has survived and grown with the help of dedicated parents and continuing attention to the mission of low-cost Catholic Montessori education. That, said co-founder Catherine Maresca, "hasn't changed a bit" since the school opened in her living room with 12 pupils.

Now in a more spacious old school building behind the St. James Catholic Church on Rhode Island Avenue, the school's biggest problem remains balancing its goals with a budget the boy on the floor might not have trouble counting.

Soley said that, despite the school's finances, he has been able to hire certified Montessori teachers who feel at home with the school's goals. The system hits a big bump when a teacher can't come to school. A teacher was sick the day the girl pushed the boy, and Soley was trying to cover the class and keep up on his responsibilities for educating the children in religion.

"We have quality players, but a weak bench," Soley said.

"With $250,000, we really can't afford support staff," Walsh-Mellett said, "so we end up running kind of a lean ship."

"Lean ship" may be an understatement. "How in the devil can they pay their bills?" asked Tim Seldin, president of the national Montessori Foundation in Sarasota, Fla. Seldin estimated the average Montessori school's tuition in the D.C. area would be about $8,000 to $12,000.

"They have to have everything worked out. We're talking sweat equity from the teachers, parents pitching in, low or no rent and substantial private donors," Seldin said. Sweat equity, parents and low rent have been taken care of, but still Soley wakes up wondering how to make the school better and pay the phone company at the same time.

The school just recently added health benefits for teachers, trying to offer more to help compensate for relatively low pay. Teachers start at about $23,000, about $10,000 less than for comparable jobs in area public school systems.

"The teachers are here because we provide something they seek, a community that really values education," Soley said.

The school also relies on parents, who participate in a co-op program, to keep the school operating.

Each parent must donate 30 hours each year to the school to perform maintenance tasks such as cleaning (the bathrooms are a perennial favorite), staffing the library, aiding in the classroom and leading the school's fundraising efforts.

"It puts pressure on the parents to be involved, because they know if they don't do their job, the bathroom is going to be dirty," Walsh-Mellett said.

When her older children attended the school in the 1990s, Kristy Malochee annually packed a tractor-trailer's worth of peaches into her living room to turn it into a fund-raising base camp.

Malochee, who still has children in the school, said the mandatory workload rarely needs to be enforced. "Parents want to do what they can for the school, and it shows in the education," she said.

Soley said he wonders, though, "Do we have enough to offer? No gym. No music program. We got real gifted parents that make this a better school."

One parent owns Joe's Movement Emporium, where the students attend tumbling class once a week. Others lead soccer games in a nearby park or teach the students skills. One mother sprinkles Spanish into the children's vocabulary while others teach weaving, dance or help with prayer.

Parents have been involved since the school was founded by the Christian Family Community, a group of parents and soon-to-be parents who were looking for a Catholic Montessori school that could be affordable. Looking for a way to make it work, the founders settled on Sofia Cavalletti's 48-year-old Catechesis of the Good Shepherd technique to combine Montessori with religion.

"We tell them the story of the shepherd and his sheep, but we don't force it on them," Walsh-Mellett said. "We let them discover what we mean by the story and they can act it out with toys. We ask, 'Who do you think those sheep are that the shepherd loves so much?' and you should see how they react when they figure it out."

"I went to a completely different type of Catholic school with large classes, where you wanted to stay out of the way," Kristy Malochee said.

She said she and her husband "realized that we could be involved in creating a school where our children would go, where they would be respected and allowed to grow both educationally and spiritually."

"We jumped at the chance," she said.

Teacher Kristi Medley, above, works with Sharada Weaver, seated, as Abbe Miller, second from right, Evan Gregory, right, and other students at the Christian Family Montessori School play around them. School Director Robert Soley, below, uses songs to teach Jenny Guzman, from left, Brandon Webster, Evan Gregory and La Rita Crews. At right, Noah Jones, left, and Will Harris spend some time in the school's reading room.Robert Soley works with Margaret Wright, right, while Eden Gregory play with logics blocks, blindfolded to build awareness of shapes.