The boys each have a cake box. They're trying to determine what on earth we need if we are using BOTH boxes to make a larger cake. How are we going to double the 2/3 cup of water the recipe requires if Mom doesn't let us just fill the measuring cup to the 2/3 level twice? Hmm... Ok, but we know the three eggs becomes six eggs, and the half cup of butter becomes ONE cup of butter. Mom has to help us on the water problem, though.