Two clever pi puns are "Math majors are good pi makers" and "Finding the diameter of a circle is as easy as pi." Both puns play off the identical sounds but different meanings of "pi" as a mathematical term and "pie" as a common noun.
Other similar pi puns include: "The roundest knight at Sir Arthur's table was Sir Cumference, who gained weight by eating too much pi," and "The arrogant math teacher had to eat a slice of humble pi when he miscalculated the area of a circle."
Two pi puns involve movies: "The movie critic saw 'American Pi' and gave it a rating of 3.14," and "The admission for the movie 'Life of Pi' was $3.14."
Some pi puns are funny but not accurate, such as, "A perfectly spherical pumpkin makes excellent pumpkin pi" and "3.14 percent of sailors are pi-rates."
A few jokes contain puns on pi. For example, a mathematician says to a baker, "Pi r squared." The baker says, "No! Pies are round and cakes are square." Two other pi jokes are, "What do you get when you divide the circumference of the sun by its diameter? Pi in the sky," and "What do you get when you divide the circumference of a bowl of ice cream by its diameter? Pi a la mode."