Showman, scholar, savant... cashier? Meet David Teitel, a man who knows more about numbers than you could ever imagine. He's worked as a cashier at health food stores since the mid-1980s. He enjoys sharing history facts, baseball statistics and arithmetic with customers — he’s famous for his numbers knowledge. After dropping out of school and struggling with mental illness, David began his career in customer service at an independent cheese store in Kensington Market in Toronto. He’s spent more than 30 years as a cashier and entertainer at health food stores. After years of wrestling with personal demons, David found an environment that’s a perfect fit for his playful nature.