You have seen these in your kids logic/math books, where you get a pattern of numbers and you are supposed to guess the next one. Now it's your turn. Guess which is the next number in each group?
17, 9 1/2, 9, 10, -28 1/2, 25, 1, 0, 8, 8 1/2, 12 1/2, 1/2, 7, 7 1/2, -2 1/2, 1, 9, 7 1/2, 2, 20...