Personalized Math Genius Frog Long Sleeve T-Shirt. A happy green frog holding a banner that reads Math Genius is a humorous gift design for mathematicians, math school teachers and students. 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