Personalized Pi Day Funny Math Pie Long Sleeve T-Shirt. Funny Pi Day math teacher or student Long Sleeve T-Shirt - White with pi symbol pie. 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