Personalized Happy Pi Day Math Lover Party Toddler Full Zip Hooded Jacket. Pi Day math themed Toddler Full Zip Hooded Jacket - Black has pi symbols in a pie. Fun gift for a geek, math teacher, college math major or any math lover. 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.