The symbol for Pi (π) comes from the 16th letter of the Greek alphabet which is written as “π”. When used in mathematics, this symbol stands for a constant which is the ratio of a circle’s circumference to its diameter. This is approximately 3.14159. Remember using the formula C = π d in high school ? This formula is used because the circumference of a circle is about three times the diameter.
We classify Pi as an irrational number because it cannot be written as a simple fraction. The decimal goes on and on forever without ending or repeating any numbers. In other words, it is infinite. While only a few digits are needed for typical math calculations (we usually use 3.14), mathematicians (not me) have calculated Pi to over one trillion digits beyond its decimal point. Pi’s unlimited nature makes it a fun challenge to memorize, but I doubt if anyone has memorized a trillion digits! Now there is a great bonus assignment for some math teacher to try!