Blaise Pascal (1623-1662) is known today as a brilliant French mathematician, physicist, inventor, writer and Christian philosopher. In 1642, he attempted to help his father, a tax collector, deal with the repetitive arithmetic calculations that were part of the task of reorganizing the tax revenues of the French province of Upper Normandy. He was thus motivated to develop and invent the only functional calculator of the 17th century, known as the Pascaline, in 1645. It could add and (indirectly) subtract two numbers. It could also multiply and divide by repetition. In 1649 a royal privilege, by Louis XIV of France, gave him the exclusivity of the design and manufacturing of calculating machines in France. He designed the only functional calculator of the 17th century.
As far as I can tell, nine Pascalines still exist today. Four of them are on display at the National Conservatory of Arts and Crafts (CNAM) museum in Paris, France. There is also an interesting video that explains how this fascinating mechanical calculator worked. I encourage you to watch, learn and explore this intriguing bit of math history and technology.