c. 1543-1643

Dutch mathematician who made the most accurate calculation of π up to his time. In 1600, Anthoniszoon and his son calculated the number to seven decimal places, or 3.1415929. Today mathematicians know π to be an irrational number, or an infinite decimal, and have corrected Anthoniszoon's seventh decimal place. Thus it is more accurately represented as 3.141592653589793238462644....