Jeanna Duerscherl | The Roanoke Times

Tyler Bradford, Alek Patton and Blake Marvin (front to back) track down a geocaching clue Tuesday using a GPS unit.

Holly Bishop helps Blake Marvin (front), Alek Patton and Tyler Bradford get started on their scavenger hunt using a GPS unit at Herman L. Horn Elementary.

The devices were donated to the school system.

The clues are: Ice and snow cover 98 percent of it, it is used mostly for scientific research and it is home to seals, penguins and whales.

"It's Antarctica," Tyler Bradford, Blake Marvin and Alek Patton said simultaneously.

Marvin marked the icy continent on a map and Bradford and Patton vied for the hand-held Global Positioning System device. Then the trio of fifth-graders from Herman L. Horn Elementary in Vinton trekked across the schoolyard in search of the next set of clues.

It was a digital scavenger hunt; an exercise in geocaching to reinforce a Standards of Learning lesson in global studies.

"It takes the paper and pencil out of learning," said Holly Bishop, an information technology resource teacher with Roanoke County Public Schools.

The students already learned inside the classroom about the continents' geographic locations and features. Bishop said the geocaching exercise emphasizes what already was taught in Amanda Lusk's fifth-grade class and it can be used to measure how many students master an SOL objective.

The first of the hand-held GPS units arrived in Roanoke County's elementary schools last spring as gifts from the Blue Ridge Teacher Training Institute. Grants funded the purchase of some 40 more units. Each device is about the size of a cellphone and comes with lots of bells and whistles. The students use only a couple of the product's features, one of which is a joystick.

"They are familiar with joysticks because they all have PlayStations and Nintendos," Bishop said.

For Tuesday's exercise, the students used the joystick to select caches numbered one through seven. The GPS' antenna communicates with satellites to plot the distance and direction of the chosen cache. The distance is displayed in feet, and the direction is shown on an electronic compass. Bishop planted the caches (plastic food containers with clues inside) and programmed the location of each into the GPS device.

Geocaching can be used with virtually any subject and with just about any age. Younger students need more help than older students, such as the fifth-graders who worked in small groups without much assistance from the teachers. So far this school year, Bishop has used geocaching in art, math, music, social studies and even physical education lessons.

"We have no control over what is in an SOL -- Virginia does that for us," Bishop said. "But we can control how we teach it."

Geocaching presents students with a 21st century way to learn.

The GPS device is "really helpful and it's also fun to use," said Savanna Woolwine, 10. "You can walk around and it will help you find stuff."

Geocaching has grown popular over the past decade as global positioning technology has flourished. Databases of hidden caches are posted on the Internet and high-tech games of hide-and-seek have become family hobbies.