Pascaline is a forerunner of the modern calculator. It was invented in 1642 by the French philosopher and mathematician Blaise Pascal and is a machine that allows you to add and subtract, while taking into account the carryover.
For a long time it was considered the first invented mechanical adder, although this merit would go to Wilhelm Schickard’s calculator. Its notoriety was amplified by the accurate description contained in the Encyclopédie, which made it the reference point for the realization of many successive calculators.
About 50 specimens of the Pascalina were built for operations both on a decimal basis and in the monetary unit of the time. In particular, the first copy was built by Pascal to help his father, a tax official, to manage his own accounts and, therefore, worked in lire, made up of twenty money, made up of twelve denarii.
Technically, referring to the decimal version, the Pascalina was composed of a series of gear wheels indicating the units, the tens, the hundreds and so on, and each was divided into ten sectors, from 0 to 9, corresponding to the numbers of the decimal system . In the financial version, the first wheels on the right had a different number of sectors.
The last machines built inspired by Pascalina were pocket adders (about 30 × 6 × 1.5 cm), such as the Addometer, which were widespread in the first half of the twentieth century, especially in the United States. In the 1960s, IBM had a plastic adder similar to the latter built for its own engineers, but operated on a hexadecimal basis. This made it possible to perform the calculations necessary in the design and programming of the first electronic calculators in a simple and inexpensive way.