Sophomore Brooke Smith was seated in Falls Church High School this week when she sent her mom a text message: “With all my best friends in class!”

The photo she sent along with the text showed rows of empty desks.

Across Fairfax County, the school year extended into summer this week, the result of an unusually harsh winter that left the system needing to make up school days. Though the schools were required to stay open to meet state instructional minimums, classes often strayed far from normal lessons, and many students skipped out.

On Thursday, the school board is scheduled to vote on a proposal that would alter the county’s academic calendar to build an extra 13 snow days into the schedule to help prevent the need to extend the school year again in the future. The hope is, schools officials said, to avoid wasted days when most students have already mentally checked out and might not even come to class.

Fairfax officials said attendance was 64 percent on Monday in the county’s high schools and dropped to 62 percent on Tuesday, meaning more than 20,000 teens didn’t come to school each day. Some schools, like Chantilly High, had empty hallways, as just 200 of the school’s remaining 2,000 students — not including the 670 seniors who graduated June 17 — came on Monday.

By Wednesday morning, for the last classes of the year, students trickled through the school’s boulevard-wide hallways in ones and twos.

“Usually you can’t move through here,” Chantilly High principal Teresa Johnson said, standing alone in the middle of a hallway intersection. “It’s usually stuffed with kids.”

For those who did show up, teachers came up with creative solutions to keep students engaged for the last few days of school, many trying to avoid the usual trick of showing movies in class.

A Chantilly chemistry class made ice cream in a lab while biology classes dissected cow eyeballs and sheep hearts. At Langley High School, students took part in a series of volunteer projects, including filling care packages for a local food bank, picking up trash on campus grounds and writing letters to armed service members deployed overseas.

At McLean High School, teachers had ballroom dancing classes, knitting and crocheting seminars, guitar lessons, a Pac-Man video game tournament, a session on building kites and a tutorial on protest songs titled: “How to write them with success and sincerity.”

McLean teachers also had a class on sea turtles and “The Lord of the Rings” creator J.R.R. Tolkien. Other sessions included serious lessons on college essay writing and what underclassmen can expect in Advanced Placement classes next year.

“I think there is acknowledgment that many families had scheduled (and paid for) committed vacation time before these three days were added to the school year,” McLean PTSA president Wilma Bowers wrote in an e-mail. “I think if the state requires these days, this approach is a great way to have some stress-free learning, have some fun (a word not often associated with school).”

McLean principal Ellen Reilly said she had seniors coming up to her at graduation asking if they could attend the unique classes the school was offering in the school’s final days.

“It was a fun day for everyone, but a day I think kids walked away with a more positive relationship with the teachers in our school,” Reilly said. “That made the day worth it.”

Principals across the county acknowledged that school attendance policies are difficult to enforce during the final days of classes. Johnson, of Chantilly High, said that since grades were submitted last Friday, it’s hard to motivate students to come to school when there is nothing at stake.

“We have already submitted final grades for the year — and kids know that – so trying to do actual work would be pretty tough,” Mount Vernon teacher Sam Hedenberg said.

Chantilly juniors Kerrell Edja and Abby Minor were the only two students in their English class, which is usually packed with 29 teenagers.

“I knew a lot of kids wouldn’t show up,” said Abby, 16. “But I thought ‘why not?’ ”

Connie Smith, the mother of Falls Church sophomore Brooke Smith, said that the schools should have added time to the end of each day throughout the year to keep from extending the calendar.

“It’s a total waste of money,” Smith said. “Why are they spending tax dollars on this?”

If the proposed schools calendar passes Thursday, the administration likely would not have to make up snow days again in June.

“We all understand that students are going to have a little bit less focus at this point in the year,” said Steven Greenberg, president of the Fairfax County Federation of Teachers. “Neither teachers or students want to be in school at the end of June. So this is another reason why we need a master calendar change.”