Personalized Math Brain Long Sleeve T-Shirt. Math Text with a happy brain is a humorous design for mathematicians, students and teachers of math. Fun gifts for birthdays, holidays, back to school and graduation. 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