In this pick-your-own-path mystery, four kids at Lincoln Elementary are invited to complete a math challenge at the school carnival. But who set up the clues? And why? Be a detective and use your money math skills to solve the case. Choose the right answer, and advance to the next clue. Choose the wrong answer, and clear text and visuals explain the math and encourage you, the reader, to try again. Friendly illustrations with a diverse cast of relatable characters will engage readers, while clear math explanations support CCSS standards for second-grade math.