CONWAY — The drive to get more young people interested in science is working, at least judging from the enthusiasm of the 350-plus exhibitors at the fifth annual Mount Washington Valley Regional Science & Technology Fair.

“It's the largest science fair in the state right now,” said Elaine Millen of Granite State College. The fair took place Thursday at the Mount Washington Valley Technology Village

Only 38 students participated the first year, she said. By the end of the day Thursday, “We'll have 600 kids come through here.”

There were plenty of projects to look at in the college classrooms and hallways of the Tech Village, and more outside in a tent jammed full of exhibits. Project topics ranged from one that tested the reaction times of video-gamers vs. non- gamers to an exploration of soil and worm respiration, and engineering design projects such as a robocam and a soccer ball launcher.

Students were happy to share their hypotheses, data and the conclusions of their experiments. Autumn Turner, a seventh-grader at Kennett Middle School, said the science fair is introduced early in the year, and midyear students pick topics. “That way it helps keep us on track.”

Some projects, she said, are season sensitive.

Turner's project studied the effect of saltwater on the growth of winter rye. “I wanted to do something with the environment.”

She would like, she said, to help make the Earth greener. She said a little bit of salt made the rye grow better.

“It makes it work harder,” she explained. “Some plants can't handle the salt.”

Kennett eighth-grader Carter Barnickel's project might have looked like child's play to some — it involved paper airplanes — but his career ambitions are anything but. Barknickel said he wants to go into the Air Force and become an aeronautics engineer.

Presenting their science projects to the public and to the judges were middle and high school students from Kennett middle and high schools, Josiah Bartlett Elementary School, Molly Ockett Middle School in Fryeburg, Maine, the White Mountain Waldorf School, Milford High School, Farmington High School and Wilton-Lyndon Cooperative School.

Not all students were present at once, as the middle and high school students were rotated through. Fifth and sixth graders from the schools in SAU 9 and 13 were not left out. Each student received a Passport to Science Inquiry, for which they practiced their skills in observing and questioning and were asked to investigate and interpret several science project displays. The fifth- and sixth-graders, Millen said, came in as observers.

“Every year, we try to engage more and more students.”

The fair was hosted by Time Warner Cable, Granite State College, Mount Washington Valley Economic Council, University of New Hampshire Cooperative Extension and the Tech Village.

Time Warner employees brought their fiber-optics van. Andrew Russell, Time Warner communications manager for New England, said the Time Warner crew would demonstrate cable splicing technology.

“That's always really popular,” he said.

Russell said a couple of dozen Time-Warner employees were helping out at the fair. Calling it “an amazing event,” he said that it gives the employees a chance to “get right up with the kids, get them excited about technology.”

He said these students are the ones who come up with inventions such as 4D-TV.

“We're so thrilled to see it grow so much. Every year there's just some amazing projects.”

The top three winners in each category, he said, receive cash awards — a motivating factor. Supporting the science fair goes along with Time Warner's Connect a Million Minds, an initiative to “Inspire a new generation of problem solvers.”