"My Password is Pi" Funny Math Nerd T-shirt for Teachers Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Machine wash cold with like colors, dry low heat Funny Pi-Day math shirt for students, teachers and software engineers. Wear it to work at the IT department, school, math club or competitions. Great gift for mathematics professors, math nerds, geeks and mathletes. "My Password is the Last 8 Digits of Pi" Funny Math Nerd T-shirt. Gift for math teachers and students. Lightweight, Classic fit, Double-needle sleeve and bottom hem