Personalized Pi Day Math Party Buffalo Plaid Toddler Full Zip Hooded Jacket. Funny Pi Day symbol for a school math party or just to celebrate a love of Pi 7.5 oz., 60/40 cotton/polyester. Jersey-lined double-needle hemmed hood. Pouch pockets for all their treasures. Coverstitched shoulders and armholes. Coverstitched rib waistband and cuffs.