Here is a clever blend of humor, math wizardry, and business know-how. As it captures the one-of-a-kind bond between brother and sister, this poignant novel also subtly explores how arguments can escalate beyond anyone's intent.

For a full hour, he poured lemonade. The world is a thirsty place, he thought as he nearly emptied his fourth pitcher of the day. And I am the Lemonade King.

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 even more important, if their fight will ever end.

The five books in this fun-to-read series are:

• The Lemonade War
• The Lemonade Crime
• The Bell Bandit
• The Candy Smash
• The Magic Trap