This lesson is optional because it does not address any new mathematical content standards. This lesson does provide students with an opportunity to apply precursor skills of mathematical modeling (MP4).

In previous lessons, students measured the length of objects by iterating same-size length units without gaps or overlaps. They learned that the number of units they used is the length of the object. In this lesson, the class makes a class quilt out of rectangular pieces of paper that they design and create borders for. Students begin by making decisions about the size of the rectangles and drawing their own rectangle based on the decisions the class made. They then determine how to make a border for the rectangle that is one cube longer on each side than the rectangle itself. Students use any method that makes sense to them to make the border. Finally, all of the rectangles are put together into a class quilt.