Eleanor is on a diet. She has decided to limit her calorie intake to 2000 calories per day, and she enrolled in an aerobics class in order to get some extra exercise. She read that aerobics burns 400 calories each hour. Today for breakfast and lunch combined, she consumed 1300 calories; however, it was her boss' birthday, so they celebrated at work with an ice cream cake. The slice of cake she ate had 655 calories. Then, for dinner, she had 3 pieces of leftover pizza at 285 calories per piece. Calculate how many extra calories she consumed to determine how long she should stay at aerobics to burn off the extra calories. Show your work.