In previous lessons, students found the volumes of right rectangular prisms represented in images in which the cubes were shown or not shown. In this lesson, students build separate rectangular prisms and put them together to emphasize the relationship between the volumes of the individual smaller prisms and the volume of the whole figure. Then they find volumes of figures made from two rectangular prisms, without first building each part. Students recognize that when the figure composed of two rectangular prisms is given, there are different ways to decompose the figure, leading to different calculations of the same volume.

What language did students use to demonstrate their understanding that the figures they worked with today were composed of rectangular prisms?