People who want their loaf of bread to stay mold-free should just take advice from 10-year-old Emma Rodgers.

A fourth-grader at Sunset Hill School, Emma recently undertook the daunting task of figuring out how mold grows best on bread for a science project she entered into the 2005 Douglas County Science Fair.

At right, Molly Rasmussen, her daughter Emma Rodgers, 10, and daughter Kristin Rasmussen, 10, visit with science fair committee member Stan Roth, left, after setting up Emma's project on mold at the Douglas County 4-H Fairgrounds. About 560 students have preregistered to display exhibits during the Douglas County Science Fair.

“It grows best in the dark with room temperature and some water,” Emma said Tuesday while setting up her science project, moldy bread included, at the Douglas County 4-H Fairgrounds. “People should freeze bread, so it doesn’t get moldy.”

For 54 years, the Douglas County Science Fair has allowed children in kindergarten through 12th grade to show off their science projects and knowledge. The fair takes place this week in Building 21 at the fairgrounds, 2110 Harper St.

About 560 children residing or attending school in Douglas County have pre-registered to exhibit at the science fair, said Jim Tramba, a volunteer. Douglas County Science Fair Assn. Chairman Dave Nordlund said he expected about 450 students to exhibit their science projects.

“If we have 460 or 470 exhibits, it will be a great year,” Nordlund said.

Since 1951, more than 15,000 Douglas County students have participated in the annual event.

Students this year answered questions ranging from how much water diapers could absorb to what types of music can stimulate plant growth. Their answers translated into projects set up Tuesday at the fairgrounds. Students will continue to organize exhibits this morning.

“There’s some imagination out there,” Nordlund said. “But, in the end, all the students have to learn to ask a question and learn how to answer the question, and then learn how to present their information to the judges. Knowing all of that is useful information for the future.”