Personalized Happy Pi Day Math Holiday Infant Romper. Pi Day Infant Romper - White has cute baked pie filled with math symbols. Fun shirt for students or teachers on Pi Day. Meet your new favorite outfit! Keep dressing simple with this one piece, lap shoulder t-romper. Super soft and perfect for baby's sensitive skin. 5.5 oz. 100% combed ringspun cotton premium jersey (CVC Colors are 60/40; Heather is 90/10 combed ringspun cotton/polyester)