Who invented the adding machine?

An adding machine Is a class of mechanical calculator, usually specialized for bookkeeping calculations. In the United States, the earliest adding machines were usually built to read in dollars and cents. Adding machines were ubiquitous office equipment until they were phased out in favor of calculators in the 1970s and by personal computers beginning in about 1985. The older adding machines were rarely seen in American office settings by the year 2000.

Blaise Pascal and Wilhelm Schickard were the two original inventors of the mechanical calculator in 1642. For Pascal this was the adding machine that could perform additions and subtractions directly and multiplication and divisions by repetitions, whilst Schickard's machine, invented several decades earlier was less functionally efficient but was supported by a mechanised form of multiplication tables.

Blaise Pascal (19 June 1623 – 19 August 1662) was a French mathematician, physicist, inventor, writer and Catholic theologian. Pascal's earliest work was in the natural and applied sciences where he made important contributions to the study of fluids and clarified the concepts of pressure and vacuum by generalising the work of Evangelista Torricelli. Pascal also wrote in defence of the scientific method.