Math Coach's Corner: End of the Year MATH Fun. A dodecahedron is a 12-sided geometric ball (or "geo ball", as my friend Laurie calls it). Copy two sheets of the pattern for each student on white cardstock. Ordinary paper is too flimsy. Kiddos decorate all of the pentagons before cutting them out. You can give them a theme, or just have them draw or write special memories of the year.