The Geomtric Board is a great way to visualize fractions and how different fractions can be combined to create a whole, as well as how fractions relate to degrees within a circle.  The set includes wooden fraction segments in halves, thirds, quarters, sixths and eighths which can be placed within the circle to create a whole, or to see how many degrees are in one third or three quarters, etc.  The board can also be flipped over to use the 121 (11 x 11) pegs to create a wide variety of geometric shapes using string or elastic bands (not included).  The Geometric Board measures 22.5 x 22.5 x 2.5 cm.