Mr. Mangham decides to go eat at Wendy’s. He orders his favorite, the Classic Single Hamburger. Dan, the server, asks what items Mr. Mangham would like on his hamburger. His only choices are: ketchup, mustard, mayonnaise and lettuce. Mr. Mangham decides to quiz Dan on his math skills: “Exactly how many total different ways can I order my hamburger using these toppings?” Assuming Dan does his math correctly, what is his answer to Mr. Mangham’s question?