At 1:05 p.m. on a recent school day, a dozen kindergartners at Plum Point Elementary School were sitting in a circle singing the alphabet. Some were beginning to look tired. Others were growing restless.

That's because just a few weeks ago, those same Calvert County kindergartners would have been at home or in day care by 1:05 p.m., not sitting in class listening to teacher Kim Murphy read "The Three Little Pigs."

This month, Plum Point Elementary and every other elementary school in Calvert County began an extended-day kindergarten program. Each elementary school now has one extended class that focuses on language and literacy and provides some remedial work, said Debora Harris, the county's teacher specialist in early childhood education.

Full-day kindergarten classes are surfacing everywhere as school systems search for ways to head off the need for remedial work in the later school years. In addition to Calvert County, Charles County has one full-day kindergarten class at Mount Hope/Nanjemoy Elementary.

The theory is simple: Early intervention can help deter academic shortcomings later.

"The greatest impact on student achievement could be made with the younger children," Harris said.

So when the rest of the kindergartners at Plum Point Elementary gather their belongings and run out to the school buses at 11 a.m. each day, 12 youngsters stay behind for a half-hour of lunch, a half-hour of recess, three more hours of instruction and no nap time. All of the children begin their day at 8:15 a.m.

School officials spent the first month of school observing and testing students to determine who would benefit most from the full-day kindergarten class. Some of the skills they tracked were language development, math and science thinking and the ability to follow directions. The enrollment might go up--teachers in the regular kindergarten class will continue to observe their students for potential all-day kindergartners.

"We target students who may not have the necessary readiness tools for school success," Harris said.

Parents had the option to turn down the offer for a full-day class. Linda Wood, whose son Sean Alley was one of the most energetic of the bunch, said she agreed to have her son placed in the class to keep him up to speed. "I'm thinking it's getting him prepared for next year, the first grade," she said. "It's putting him in gear and working on things that he may be behind on."

At Plum Point, the extended day is all about the basics for the all-day kindergartners. Reading is the thrust behind much of the added instruction time.

Murphy reads books with her students every day and encourages them to keep a journal. She regularly leads them in song to get them to understand sounds and language through rhythm and rhyme.

On a recent day, they joined her in reading "The Three Little Pigs."

"I'll huff, I'll puff and I'll blow your house away," the youngsters said in unison as she reached the climax of the story.

Murphy acknowledges that a full day of school for the 4- and 5-year-olds can be taxing. That's why she tries to vary their activities--reading for a half-hour, drawing for another half-hour and doing group work here and there. Most of the time, they don't seem to mind that they're in school all day, she said.

Tyeshia and Myeshia Reid had no problems scurrying into a corner to read "Oh, A-Hunting We Will Go." Both thumbed through the book and chanted "A-hunting we will go, a-hunting we will go."

Staying on task became more difficult when the class went to the library at 2:15 p.m. for some more reading. Several hours into the school day, keeping the kids attentive proved no small feat.

As Peggy Demedis, the media specialist, read "The Big Red Barn" to the children, Terri Lynn Christian rested on the floor for a few minutes while others fidgeted as they sat on the carpet.

But when it came time for dismissal at 2:55, the kindergartners were again attentive as they collected their book bags and lunch boxes and waited for their bus number to be called.

"I think as time goes on, they're going to get used to it," Murphy said.