Although the curriculum scope and sequence does not introduce volume until late in the year, students are required to answer volume on a number of standardized assessments during the winter and early spring. With that in mind, I'll introduce volume through a number of fun activities.
The first will be the activity above. Students will make a number of cubes or rectangular prisms from nets. We'll discuss the volume of each prism or cube. Make the snowpeople and then figure out their total volume. Later students will be able to make their own nets and snow people, then find out the volume of those creations.
We'll build out this learning in a number of other ways too, but this is a fun way to introduce the concept just before the holiday break.