"Fantastic." Using a combination of Braille and speech, a teaching device with a deep, computerized voice can offer instant praise to blind and visually impaired students struggling to grasp mathematics.

Introduced on Thursday, the speech assisted learning system, dubbed SAL, is a flat, notebook-sized tool that can help students tackle activities ranging from learning to count to solving difficult calculus problems in Braille, all with limited attention from a teacher.

"It's an absolute new era in education for blind children and adults because it puts the student in charge of learning for the first time," Sally Mangold, SAL's creator and a visually impaired educator, said in an interview.

"Blind people who are literate are more employable, more independent and more satisfied," she told Reuters after a news conference at which the device was demonstrated.

Students insert a special Braille sheet with a barcode into the device and its computer reads the words and symbols on the page aloud. A student can press a character or symbol and Sal will pronounce it.

A second press will spell a word or define what a certain mathematical symbol means. SAL can even describe a picture.

The device also helps teach Braille, a system of writing for the blind that uses raised dots felt with the fingers.

Although experts urge its use, Braille has been taught less frequently in recent years as more blind children have been put in regular classrooms and other tools such as audio tapes have become more popular. "We can teach Braille in ways we never thought before," said Mangold.

The SAL device, which costs $4,600, is made by freedom scientific of St. Petersburg, Florida.

*** Braille Teacher Shortage **** The SAL system also may help combat a severe shortage of Braille teachers.

"Any tool, especially one like this, that is going to facilitate learning how to read Braille is going to have an outstanding reception in the blind and visually impaired community," said John Stanford, president of the International Organization for the Blind, a Florida group that promotes the teaching of Braille in early childhood.

The foundation estimated that as many as 5,000 more Braille teachers are needed to educate 93,000 students below the age of 21 who have a visual impairment.

In the United States, the American Foundation for the Blind estimated that of the 10 million people who are legally blind or visually impaired, only 10 percent of students, or about 5,600 people, and 8 percent of adults, or 104,000 people, use Braille as their primary tool to read.

Many more use it for smaller activities including reading floor numbers on an elevator or playing cards.

The SAL system will never replace teachers but should expand learning opportunities. Mangold said the U.S. Department of Education has expressed an interest in buying some of the devices.