The quantal hypothesis is central to the modern understanding of how a neurotransmitter is released from synapses. This hypothesis expresses that a neurotransmitter is packaged together in quanta that are released probabilistically. The experiments that led to the quantal hypothesis are often related in introductory neuroscience textbooks, but these experiments use advanced concepts that can be unfamiliar even to advanced students. To remedy this, the author has developed a tangible model of the concepts associated with the quantal hypothesis, suitable for an interactive classroom demonstration. These activities were designed to explain the physiology experiments of Katz (who formulated the quantal hypothesis in the 1950s) and the application of probability theory. The activities can be presented interactively in a discussion section or laboratory, or they can be streamlined and covered during a lecture. These activities will help students appreciate the trial-by-trial nature of the quantal analysis performed by del Castillo and Katz and Boyd and Martin. (Contains 3 figures and 1 footnote.)