This lesson focuses on the conceptual understanding of the formula for volume. It includes teacher instructions on how to use a free website (linked to instructions) that helps students visualize the idea of looking at volume through layers of blocks. The lesson includes examples and checking for understanding through an appointment book activity. It also scaffolds the lesson to move from rectangular prisms to triangular prisms using the same free website. No answer key is included since it's best to work through the problems to anticipate student reasoning. Its a great lesson to introduce the concept of volume, or as a review in later courses.