Personalized Happy Pi Day Math Lover Party Long Sleeve T-Shirt. Pi Day math themed Long Sleeve T-Shirt - Pink has pi symbols in a pie. Fun gift for a geek, math teacher, college math major or any math lover. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL