This is the most carefully and completely documented use of the "The Handshake Problem" (also known as the "Glass Clink Problem") that you can find. It spans 5 days worth of lessons, homework assignments, enrichment and an assessment.The beauty of the "handshake problem" is that it can be looked at as a way to represent a problem visually through the use of points and connecting edges, but it can be investigated as a sequence of triangular numbers. This is then be compared to other types of sequ