Make Math Moments Academy › Forums › MiniCourse Reflections › The Concept Holding Your Students Back › Lesson 54: Building Multiplicative Thinking Through Problem Based Lessons – Discussion › Reply To: Lesson 54: Building Multiplicative Thinking Through Problem Based Lessons – Discussion

Stacking Books is an activity I use to introduce slope. With students trying to figure out how many books to stack in order to reach the ceiling. This can be used to at first with the additive approach because figure just the number of books. Then we can find the width of each book and see how many can be stacked to the height of the ceiling.
Then to incorporate more multiplicative thinking is to extend the task. We can create a stack with a group of 3 books. Then you ask about many of these stacks can be used to get to the ceiling. Finally you can ask students to figure out how many of these stacks of 3 books would be needed to reach the top of the building (3 floors).