Zaid and Zara are twins-but that doesn't mean they get along. Especially not when it comes to math. Zara seems to solve problems in her sleep, while Zaid would rather do anything else. But when their class heads to Carnival Day, everything changes. There's one epic prize up for grabs-the biggest gumball machine they've ever seen! At first, Zaid tries to go it alone. But as the challenge gets tougher and the gumball machine gets closer, he and Zara start to wonder: what if they actually make a great team? Will they figure it out in time? Or will the prize-and the math-slip through their fingers?