In 1642 the young Blaise Pascal built a machine to help his father, a tax collector. The Pascaline added and subtracted by turning gears. To multiply, however, you had to repeat the addition by hand, many times. Leibniz saw a Pascaline in Paris and wanted to go further: a machine that would multiply and divide on its own. Multiplying is adding and shifting The trick is the same as in long multiplication at school. To multiply $23\times14$, we split 14 into $4+10$: