High school math π represents pi, a mathematical constant, which is the ratio of the circumference to the diameter of a circle. The approximate value is about 3. 14 1592654.

Because π is an irrational number, it cannot be completely expressed by fractions (that is, its fractional part is an infinite acyclic decimal).

History of pi:

Many mathematicians in ancient China made great efforts to study this subject and achieved gratifying results. On the basis of predecessors' research, Zu Chongzhi continued to make in-depth and systematic research on pi. After many calculations of 1000, he finally worked out the exact pi of 1500 years ago.

Zu Chongzhi calculated pi between 3. 14 15926 and 03. 14 15927. He became the first scientist in the world to calculate pi to seven decimal places.