Blaise Pascal, Mechanical Calculator - 19 years old

As a child prodigy, Blaise Pascal was educated by his father, a successful French tax collector. His creation of an adding machine was the groundwork for the modern day calculator, which he created in 1642 while helping his father at work.

Pascal's father spent all day conducting complex mathematical calculations as a tax collector for the crown. Little Pascal created a wooden box that had 16 separate dials and when each dial was turned, additions and subtractions were able to be done quickly.

Blaise Pascal makes it to one of the top spots on our list because he was able to do something that others had tried and failed. In fact, Leonardo da Vinci attempted to create a calculating machine that was similar to the one created by Pascal.