Personalized Black Math Universe Toddler Long Sleeve T-Shirt. Math is the language of the universe text in black and white. Fun gifts for math lovers at birthdays, holidays, graduation and back to school. 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.