Bringing this irrational constant to your table top is sure to spark up conversation. It has been a helpful tool in identifying the true geeks in a crowd! Great as a gift for that new college grad or for the math geek in your family. 

Custom-engraved, high-quality white corian, measures 3.75" square (that's right, square, not circle). Set of 4 coasters, colored C, M, Y, and K (for the math geek with a passion for graphic design)