On the basis of predecessors, Zu Chongzhi accurately calculated the specific content of pi. According to the records, the method he adopted should be "cyclotomy".

During the Qin and Han dynasties, people's understanding of the relationship between circle and diameter has formed a preliminary concept, that is, the diameter is three times a week, that is, the circumference of a circle is equal to the length of three diameters. However, the water in this place is relatively large, so there is a saying that there are more than Wednesday, but no one can answer the specific number. It was not until Liu Hui came here that a more scientific calculation method of pi was put forward, which is the "secant method". What is cyclodialysis? It is to calculate the area of a circle inscribed with a regular polygon and infinitely approach the area of the circle to determine how big the area of the circle is. At that time, Liu Hui's achievements were quite amazing. He accurately calculated that pi was 3. 14.

On the basis of predecessors' achievements, Zu Chongzhi began to calculate pi himself. According to the conditions at that time, the process of calculating pi in Zu Chongzhi was quite hard, because there were no Arabic numerals at that time, so we could only use the method of counting small pieces of bamboo. It is conceivable how heavy the calculation work he faced at that time was. Liu Hui's secant method is needed to determine the circumference of a circle, and then the exact value of pi can be determined. Errors and arithmetic errors may also occur. Zu Chongzhi's perseverance and patience are really admirable.

It is worth mentioning that it took western mathematicians more than one thousand years to get the same density after Zu Chongzhi determined the exact number of pi.