This Application Problem is a part of the Lesson 7, Unit 5, Grade 1. Peter set up 5 rectangular prisms to make 5 towers. He put a cone on top of 3 of the towers. How many more cones does Peter need to have a cone on every tower? This Application Problem presents a compare with difference unknown problem type using easy numbers. Before moving to Concept Development, link the Application Problem question with the more challenging comparison question of How many fewer cones does Peter have than rectangular prisms?