This activity introduces the idea that computer scientists measure information by how "surprising" a message is. Learners play the game "20 Questions" and use the number of questions asked as a measure of the value of "information" in the answer. While this is not an intuitive idea, an image of a "decision tree" for guessing a number between 0 and 7 illustrates the relationship between the answers to the questions (yes=1 and no=0), and the answer (so if the answer is 3, then three questions whose answers are no, yes, yes yields 011, which is 3 in binary.