There was a brief period through the 1960s into the 1970s when the last word in electronics was the calculator. New models sold for hundreds of dollars, and owning one made you very special indeed.

Indian teenager Aaryan Shulka performs calculations in his head quicker than most people can use a calculator. At a recent ...

Aaryan Shukla, a 14-year-old from Maharashtra, broke six Guinness World Records in a day for mental calculations, including ...