This formative evaluation gathered feedback from teachers and their fourth grade children in response to two activities included in the Cyberchase Teachers' Guide. The user-based feedback will assist with the design of new school-based materials. The general goals for the research were to explore reactions to the guide; assess appeal and difficulties in implementation of two activities; estimate comprehension of activity content; and evaluate teacher interest in further activities. Cyberchase is the Emmy Award-winning mathematics series and website on PBS KIDS GO! using broadcast, web, new