High school educators have been using graphing calculators in math and science courses for years, but the arrival of affordable, more versatile personal digital assistants (PDAs) in schools—coupled with the addition of software that turns these handheld computers into graphing calculators—has some educators wondering if it's time for a change.

The news doesn't bode well for the likes of Texas Instruments Inc. (TI). Clearly the dominant seller of graphing calculators to schools, TI has had to search for ways to add computer-like functionality to its machines or risk losing control of a market it has dominated since the early '90s.

For educators, the changes mean difficult purchasing decisions. PDA makers contend their devices are more versatile and simpler to use, but TI—which makes the popular TI-83 calculator—maintains its machines are better accepted, tougher, and cheaper.

Designed specifically with the classroom in mind, graphing calculators are still the preferred tool for instruction. TI says it sells 2.5 million graphing calculators a year, and 25 percent of these sales are derived directly from school districts, while the lion's share are purchased by parents and students.

But with PDA software packages now being designed with education in mind, PDA proponents say it's only a matter of time before educators begin to favor the more versatile devices.

"A whole host of things become possible that have never been possible on traditional handheld calculators," said Wayne Grant, president of Imagiworks Inc.

Imagiworks is the maker of ImagiMath, a software program for Palm handhelds that turns the PDA into a graphing calculator.

Grant says the program is ideal for high school math and science classes, because it cuts down on the number of buttons and functions students must learn to get results.

"With traditional calculators, a large part of students' attention is focused on operating the interface as opposed to where it should be—on the graph," he said.

Makers of wireless PDAs say the machines are not meant to replace the graphing calculator but should been seen as all-purpose investments that can play any number of instructional roles.

"What we are trying to do is create a device that is the Swiss Army knife of learning," said Mike Lorion, vice president of education at Palm.

For $39, educators can purchase Palm's Mobile Mentor Series. The software bundle offers 11 different applications, including the ImagiMath program, for a variety of networking and instructional uses in schools.

Increased versatility is certainly a factor for educators, many of whom have considered purchasing PDAs for use in schools.

"The PDAs allow students to keep track of homework, check eMail, and take notes.... With graphing calculator functions and programs, I am considering [PDAs] for purchase" for the new school year, said Sandra Becker, director of technology for the Governor Mifflin School District in Pennsylvania.