Approximation Day celebrates the mathematical constant π (pi). It is observed
on July 22, due to π being roughly equal to 22/7.
fractional approximation of π ,22⁄7, resembles the date July 22 in the
day/month format, where it is written 22/7. Pi Approximation Day is therefore
celebrated on July 22.
geometry, pi is defined as the ratio of a circle's circumference to its
diameter. July 22, often written as 22/7, is an appropriate day to explore pi,
since 22 divided by 7 is an approximation of pi.
Approximation Day is celebrated in a number of ways, including contests to
memorize pi to the most decimal places, solving math problems involving pi,
discovering the history of pi, ruminating on how life would be different
without pi and—of course—eating pie.