Lisa and her Boston terrier, Penny, are back in this delightful look at probability. Readers will follow Lisa’s teacher, Mr. Jayson, through his lesson as he uses different groups of colored jellybeans to introduce the concept and vocabulary of probability to his class. For weekend homework, the students must think of events that will, might and can’t happen; that have a tiny chance or are impossible; that have three outcomes that are equally likely to occur; and that have several unequally likely outcomes. As usual, Lisa uses Penny’s antics in most of her answers, many of which will tickle children’s funny bones. Leedy’s illustrations add both humor and understanding. Well-planned pages with patterned backgrounds, crisp figures and no extraneous clutter help readers focus on the concept, while clear language, simple explanations, repetition and a solid dose of humor make this a winner. Leedy scores again with this engaging mathematical tale. *(Picture book. 5-8)*