Most of the classrooms at Mount Vernon Community School were empty last week, and boxes of textbooks were piled high in the hallways. But teacher Larry Ciarelli's not-quite-kindergartners were tackling a bold agenda on their third day of class in the school's kindergarten preparation program: They were going to learn about triangles, the letter B and the colors green and orange.

"We're going to do another Skittles graph today," Ciarelli announced one morning, eliciting cheers from the 12 wiggly 5-year-olds.

Later, as the children glued slices of paper pepperoni and bell peppers on pieces of cardboard pizza, they seemed blissfully unaware that the fun tasks could help place them -- and the Alexandria school system's nearly 300 other "K-Preppers" -- at the top of their class in the coming school year.

That's what school officials hope, at least, and they have good reason. According to a district evaluation, the innovative two-week program, which aims to familiarize incoming kindergartners with school before all the big kids come, worked so well at two Alexandria elementary schools that the district decided to add it at 10 others this summer. K-Prep is not offered at Tucker Elementary because that school runs on a year-round calendar that began in July.

"When you get a little orientation that's just for you to get to know the school and the principal . . . you know what you're doing," said Cathy David, former director for elementary programs who was recently promoted to assistant superintendent for curriculum and instruction. "And you do see a difference."

The K-Prep program was launched in 2000 as an experiment at Lyles-Crouch Traditional Academy and Jefferson-Houston School for Arts and Academics, new schools where administrators believed kindergartners might benefit from a crash-course in letters, numbers and classroom routines.

A 2003 evaluation of the program at those schools made some stark findings: Children who had attended K-Prep scored higher on literacy and math tests at the end of kindergarten than other students, and more of them moved on to first grade. K-Prep students also had better attendance in kindergarten.

The results were even more dramatic for the program's target students: those who had not attended preschool, who make up about half of the district's 1,000 kindergartners. None of them, for example, were retained at the end of kindergarten, while 13 percent of the students who didn't attend preschool or K-Prep were held back.

Many studies have found that early childhood education helps children succeed in school. But school system officials said they have never heard of such a short program yielding such dramatic results. Some said they think the secret to K-Prep's success is not its academic rigor -- teachers are given broad curriculum objectives and are expected only to introduce students to letters and numbers -- but its emphasis on acclimating students to school and each other.

"All of us, when we start a new high school, start a new college or start kindergarten, have some trepidation with the experience," said Monte Dawson, director of the school district's Monitoring and Evaluation Department. "To be able to ease into the experience lends itself to a degree of comfort. It also provides some early opportunity for success. If school is a negative from go, it's going to be an uphill struggle."

The price of expanding the program, which is free and optional to students, was about $95,000, David said. But the program could pay for itself if K-Prep students continue to advance to first grade at the same rate, Dawson said. It costs the district about $11,500 each time a student repeats a grade, he said.

"Early childhood education is a good investment," he said.

Even if Ciarelli's students had known that last week, they probably wouldn't have cared. They were too busy naming the things they liked about school. Chelsea Rodriguez said she was a fan of learning shapes. Christopher Senf said he preferred nap time. Sabra Rose said she loved her colorful classroom.

"They're just so excited!" Ciarelli said. "I love it."

Mount Vernon Principal Lulu Lopez said that enthusiasm was an accomplishment in itself.

"We're not going to have them reading at the end of two weeks," she said. "But the children will feel comfortable here."

Sheree Stephens helps Umme Rubab, left, and Jaime Romero during a lesson on triangles. Nearly 300 students are enrolled in Alexandria's "K-Prep" program, which is being offered at 12 city elementary schools this year.Jaime Romero, left, and Zachary Struckoff play with paper "pizzas" at Mount Vernon Community School in Alexandria. Larry Ciarelli leads a weather lesson for his K-Prep class, which aims to help pre-kindergartners adjust to school.Umme Rubab, left, and Zachary Struckoff say the Pledge of Allegiance. A study found that children enrolled in K-Prep did better in kindergarten.