Personalized White Math Smile Toddler Long Sleeve T-Shirt. A math smile with the smiling face composed of the word math is a funny gift design for mathematics students and teachers. A classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.