A calculator is a device that performs some mathematical operations on numbers. A basic calculator can perform simple arithmetic operatios such as addition, substraction, division and multiplication. Scientific Calculators can perform wide range of calculations not limited to sine and cosine calculations but also some complex exponential calculations. French mathematician Blaise Pascal invented the adding and substractiong calculator using his mechanical knowledge. This calculator consisted of gears and other moving parts to perform addition and substraction.
Origin of the calculators dates back to 9th Century abacus, developed in China which consisted of small beeds to perform the calculations required. World's first scientific calculator is developed by Hawlett Packard which is an handheld calculator, the HP 35.