This demonstration is part of over 225 elementary (6-12) math demonstrations which are available on EdVid’s online video delivery system. For more information on this service go to http://www.edvid.com. EdVid also has a growing library of elementary one language, geometry and geography demonstrations. In total we have over 600 videos on Montessori issues, school leadership, assistant training, student recruitment, parent orientation, staff development and more – well organized by content and scope and sequence. Edvid also offers online courses and a broad range of DVDs. These math lessons are demonstrated by Robyn Breiman of the Montessori Elementary Teacher Training Collaborative.