How many people do you need to gather in order to find two individuals with the same birthday? Most people who asked this question tend to answer with a number that is much too high. The phenomenon is known as the "birthday paradox." Russell Goldenberg of The Pudding has created this interactive experiment designed to help visitors understand the math behind the birthday paradox. In this experiment, visitors are invited to share their birthday month and date. Next, they have the opportunity to see how previous visitors answered the question. In doing so, visitors can see the "birthday paradox" in action. As visitors view how an increasing number of participants answered the question, they will view an accompanying graph that demonstrates the law of large numbers. Visitors who enjoy this interactive will want to check out other projects included in The Pudding's Essays About Explainers.