Nine color-coded squares in fractions of 1/2, 1/3, 1/4, 1/5, 1/6, 1/8, 1/10, 1/12 plus a whole. Made of dense foam, these squares are easy to handle and stay put nicely. Each of the 51 pieces are 0.5 centimeters thick. 51 pieces each, bundle of 3, 153 pieces total