Hey idiot, the split check function has nothing to do with math. It's about the simplicity and ease of paying the bill when more than one party is paying. Instead of handing the server five separate credit cards and telling her how much to put on each one, then waiting for them to go process them and return to the table, you can use the function to split the bill yourself, and then each person can pay their portion right there at the table. No server involved in the entire payment process. It frees up the server's time to attend to other customers and provide better overall service, and allows your group to pay and leave without having to wait.