8 - 12 years. Evan Treski is people-smart. He is good at talking with people, even grownups. His younger sister, Jessie, on the other hand, is math-smart--but not especially good at understanding people. She knows that feelings are her weakest subject. So when their lemonade war begins, there really is no telling who will win--and even more important, if their fight will ever end. Here is a clever blend of humor and math fun. As it captures the one-of-a-kind bond between brother and sister, this poignant novel subtly explores how arguments can escalate beyond anyone's intent. Paperback. 192 pages.