Peg Cat The Lemonade Problem Author:Jennifer Oxley, Billy Aronson When life gives them a problem to solve, Peg and Cat make lemonade ? and get a lesson in bartering ? in a refreshing new math adventure. — It?s a hot day, so what could be cooler than setting up a lemonade stand? When Peg needs some marbles to keep her special marble company, she and Cat decide to sell lemonade in exchange for ten marbles a cup. ... more »But the Teens have other ideas. "Just one teensy cup for ten marbles?" says Mora. "Uh, hello?" So Peg and Cat keep changing their sign until they hit a price ? two marbles! ? that has customers lining up. There?s just one problem: Peg and Cat forgot the cups! Can they barter their way back into business ? or will they end up totally freaking out?« less