This book assists high school teachers in honing their studentsâ€™ thinking by introducing them to two approaches to probability and exploring both approaches in real-world contexts. The first approach, which interprets probability as relative frequency over the long run, uses actual or simulated data from many experiments to arrive at empirical probabilities. The second approach analyzes outcomes abstractly to arrive at theoretical probabilities. The supplemental CD-ROM features interactive electronic activities, master copies of handouts, and additional readings. Topics: Probability as long run, sample spac, expected valuees, independence and conditional probability, probability models and distributions. Contents of the CD-ROM: Table of Standards and Expectations, Data Analysis and Probability, Pre-K-12, Readings from Publications of the NCTM.