Subscribe | UPI Odd Newsletter Subscribe NEW BRUNSWICK, N.J., Sept. 13 (UPI) -- Students and professors at New Jersey's Rutgers University and other schools across the country are praising a classroom tool known as the "clicker." Marketed as a high-tech "personal response device," the calculator-size clickers allow students to give multiple-choice answers to quizzes and take part in polling and student polling, the Philadelphia Daily News reported Monday. Teachers can use them to take attendance. Advertisement An estimated 2 million students in the United States are currently using clickers, which can run $35-$40, the Daily News said. Neil Sheflin, an associate professor of economics at Rutgers, called clickers "the greatest educational innovation since chalk." Sheflin said his students also enjoy using them. "The majority find that it's a lot more fun and a lot more interesting and a lot less sleep-inducing," he said.