Personalized Funny Pi Day Math Joke Keep Calm Calculate Pi Long Sleeve Creeper. funny Pi Day themed quote says keep calm and calculate Pi For chillier weather, dress baby in this soft long sleeve creeper in a great fitting 1x1 baby rib. 5.0 oz., 100% combed ringspun cotton, 1x1 baby rib. White is sewn with 100% cotton thread, Flatlock seams, Double-needle stitched rib binding on neck, shoulders, sleeves and leg openings,Reinforced three-snap closure on binding.