In this second lesson on applying surface area and volume to solve problems, students solve real-word problems of increased complexity that require them to choose which of the two quantities is appropriate for solving the problem, or whether both are appropriate for different aspects of the problem. They use previous work on ratios and proportional relationships, thus consolidating their knowledge and skill in that area. Students engage in aspects of mathematical modeling as they determine whether to use surface area or volume and consider how the constraints of the situation affect the solution (MP4).