Definition:Zu Chongzhi Fraction

Definition
The Zu Chongzhi fraction is an exceptionally accurate approximation to $\pi$ (pi):
 * $\pi \approx \dfrac {355} {113}$

whose decimal expansion is:
 * $\pi \approx 3 \cdotp 14159 \, 292$

Also known as
The Zu Chongzhi fraction is rendered variously according to the transliteration of his name into Latin characters: Tsu Ch'ung-Chi's fraction is an example.

The fraction $\dfrac {355} {113}$ is also called Metius' number, for, who discovered it independently in around the $16$th century.