Incorporating engineering in the elementary school curriculum provides students with ways of connecting, applying, and reinforcing knowledge in math, science, and design. To bring what is essentially a new discipline to K-12 education means developing and supporting new tools for the classroom, additional curriculum, teacher training, and support resources. Using LEGO materials and the ROBOLAB software as the toolset, Tufts University's Center For Engineering Educational Outreach has had significant success with our efforts to bring engineering into a number of schools and classrooms. Examining the classroom results these efforts have yielded highlights the problems and obstacles, a significant potential for expansion, as well as a number of effective practices and strategies.