Each order = 5 sheets (40 removable stickers) featuring 8 Pi Symbol Stickers (4 are 2.5 cm length, 4 are 1.5cm length.)  Great for cards, envelopes, school projects, laptops, windows, appliances etc. Stickers are acid, PVC and phthalate free.  The adhesive is mild allowing you to easily remove the stickers without any damage or leftover residue. After being applied, the bond will strengthen over time. Not recommended for outdoor use. Great for Pi Day parties!

Did you know?: Defined as the ratio of the circumference of a circle to its diameter, pi, or in symbol form, π, seems a simple enough concept. But it turns out to be an "irrational number," meaning its exact value is inherently unknowable. ... Ancient mathematicians apparently found the concept of irrationality completely maddening.