"Evan Treski is people-smart. He's 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. With just five days left of summer vacation, Evan and Jessie launch an all-out war to see who can sell the most lemonade before school starts. As the battleground heats up, there really is no telling who will win--and...