Definition:Zu Chongzhi Fraction/Historical Note

Historical Note on Zu Chongzhi Fraction
The Zu Chongzhi fraction $\dfrac {355} {113}$ as an approximation for $\pi$ (pi) was derived by and his son.

fortuitously rediscovered it independently around the $16$th century.

He did this by taking mediant of two limits $\dfrac {377} {120}$ and $\dfrac {333} {106}$ calculated by his father. This is guaranteed to generate a number between those limits, but the usefulness of the approximation was lucky.