"Fun and Games Divide by Zero" Math Nerd T-shirt for Teacher 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 shirt for teachers and students who love math. Wear it to math clubs, mathlete competitions and to class at school or college. Great gift for mathematics professors, engineers and math nerds & geeks! "Math: It's all Fun and Games Until Someone Divides By Zero" Funny Mathematics T-shirt for Math Nerds and Teachers. Lightweight, Classic fit, Double-needle sleeve and bottom hem