Zu Chongzhi

Zu Chongzhi, known as Wenyuan, was an amazing Chinese mathematician, astronomer, and inventor who lived a long time ago during the Liu Song and Southern Qi dynasties. One of the coolest things about him is how he calculated the value of pi (π) to an incredible level of accuracy - between 3.1415926 and 3.1415927. This might seem like just a bunch of numbers, but it was the most precise calculation of pi for nearly 900 years!

Also Zu found a fraction, 355/113, that is shockingly close to the actual value of pi. When you write this fraction as a decimal, it's 3.1415929 which is accurate to six decimal places. That's like getting a bullseye on a dartboard that's miles away! This fraction was the best approximation of pi that anyone could come up with using just four-digit numbers.

Zu was born in a place called Jiankang, and his family had a long history of studying the stars and planets. Because of this, Zu grew up surrounded by astronomy and mathematics, and he quickly became known for his talent. When he was still quite young, his reputation caught the attention of Emperor Xiaowu of Song, who sent him to study at the Hualin Xuesheng academy and later at the Imperial Nanjing University. These were big, important places where Zu could really dive into his research.

Sadly, most of Zu's mathematical work was recorded in a book called the Zhui Shu, which has been lost over time. However, historians believe that this book contained very advanced ideas, possibly about solving cubic equations?something that's quite challenging even for today's students! Zu didn't stop with pi, though. He also worked on figuring out how to calculate the volume of a sphere; another big deal in mathematics.

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Appreciate the work of Zu Chongzhi by trying some of the maths that this mathematician is known for.

There is an activity called Circles that you could try right now. Practise using pi to calculate various circle measurements. There are six levels of difficulty.

So there's no better time than the present to learn some mathematics from the past: let's Go!