Here are 10 fun facts about π (pi):

1. Ancient Approximations: The ancient Egyptians and Babylonians approximated pi around 4,000 years ago, with the Egyptians coming remarkably close to the actual value using fractions like 169≈3.16916≈3.16.

2. Symbol Origins: The symbol π (pi) for the ratio of the circumference of a circle to its diameter was first used by Welsh mathematician William Jones in 1706.

3. Infinite and Non-Repeating: Pi is an irrational number, meaning it cannot be expressed as a simple fraction, and its decimal representation goes on infinitely without repeating any sequence.

4. Record Digits: As of 2022, the record for calculating the most digits of pi stands at over 62 trillion digits, computed by researcher Timothy Mullican using the y-cruncher software.

5. Mnemonics: Many people use phrases or poems to remember the digits of pi. One popular example is "How I wish I could calculate pi" which corresponds to the digits 3.1415926535.

6. Fascination in Culture: Pi has a deep cultural significance and is celebrated annually on March 14th (3/14) as Pi Day. It is also associated with the beauty and symmetry of circles and spheres.

7. Legal Battle: In 1897, Indiana attempted to pass a bill defining the value of pi as 3.2. The bill never became law but highlighted the challenges of legislating mathematical constants.

8. Pi Pie Number Search Puzzles: Pi enthusiasts create "Pi Pie Number Search Puzzles," where the digits of pi are scrambled, and solvers must find certain sequences or patterns hidden within.

9. Famous Digits: The first six digits of pi (3.14159) are widely recognized and used in everyday calculations. This approximation is adequate for most practical purposes.

10. Pi in Nature: Pi appears in various natural phenomena, such as the shapes of river bends, the growth patterns of plants, and even the distribution of prime numbers.