Develop and evaluate inferences and predictions that are based on data Inference and prediction are more-advanced aspects of this Standard. The development of these concepts requires work with sampling that begins in the next grade band. As appropriate beginnings for these concepts, however, teachers should encourage informal discussions about whether or not students in other classes would reach a similar conclusion. Understand and apply basic concepts of probability At this level, probability experiences should be informal and often take the form of answering questions about the likelihood of events, using such vocabulary as more likely or less likely. Young students enjoy thinking about impossible events and often encounter them in the books they are learning to read. Questions about more and less likely events should come from the students' experiences, and the answers will often depend on the community and its location. During the winter, the question "Is it likely to snow tomorrow?" has quite different answers in Toronto and San Diego. Teachers should address the beginnings of probability through informal activities with spinners or number cubes that reinforce conceptions in other Standards, primarily Number. For example, as students repeatedly toss two dice or number cubes and add the results of each toss, they may begin to keep track of the results. They will realize that a sum of 1 is impossible, that a sum of 2 or 12 is rare, and that the sums 6, 7, and 8 are fairly common. Through discussion, they may realize that their observations have something to do with the number of ways to get a particular sum from two dice, but the exact calculation of the probabilities should occur in higher grades. ...
