PLATTSBURGH -- Melissa Caraballo pointed to the top of a large white board and scrolled down with her finger, revealing eight sets of four black dots.

"Boys and girls," she said, turning to her fourth-grade class, "we are doing one of your favorite activities, and the goal is to figure out how many dots I have up here."

Her students at Momot Elementary School smiled in anticipation, eyes front.

And three seconds after the dots appeared, she slid her finger toward the top of the board, and they vanished.

Caraballo used a SMART Board to guide her students in their multiplication lesson. Interactive whiteboards are appearing in schools around the country, replacing chalkboards, flipcharts and overhead projectors.

"It's changed the whole way of teaching and learning for kids," said Caraballo, whose classroom was fitted with a SMART Board in March 2007.

Interactive whiteboards are driven by computer software and allow teachers to access the Internet, transform notes into text, save lessons and more. The software lets users circle, zoom in, highlight, draw and erase, using fingers instead of a mouse and other tools such as digital markers.

They can also display movies, images and PowerPoint presentations and can supply substitutes with pre-recorded lessons, while providing teachers with the ability to transmit homework assignments on the Internet for students to upload.

"Many students, especially those with special needs, are more successful when you can apply something visually and give them a chance to be hands-on," Caraballo said.

She uses her SMART Board with nearly every lesson.

"The kids were reading Shiloh' the other day, and the setting is in West Virginia," Caraballo said. "We went on Google Earth at that moment and showed the difference between Plattsburgh and the characters' hometown."

SMART Boards are made by SMART Technologies, while other companies that sell similar interactive tools include Numonics and PolyVision. They run anywhere from $1,000 to more than $4,000.

"I know they are expensive," Caraballo said. "But I have seen such a huge improvement in my students."

Around 18 million students in more than 600,000 classrooms in more than 100 countries use SMART Boards, according to SMART Technologies, which introduced the first one in 1991.

A projector throws the computer's desktop image onto the interactive whiteboard, which acts as both monitor and input device.