"Calculations"

Egyptian & Babylonian calculations for the value of pi, circa the making of the disc:

The Egyptian calculation for the value of pi: 256/81 = 3.16049

The Babylonian calculation for the value of pi: 25/8 = 3.125, and both are within 1% of the value used today.

Archimedes in circa 250 B.C. calculated the value of pi was between:

Lower Bound; 223/71 or 3.1408

Upper Bound; 22/7 or 3.1428

Ptolemy in around A.D. 150 calculated pi as 3 17/120, or 3.1416, a closer value than Archimedes;

About 100 years later in A.D. 263 Liu Hui of China derived a value of 3.14159.

Today's value is: 3.1415926535......, never terminating or having repeating patterns, with 314 trillion digits beyond the value shown above.