In Lesson 15, students discover that equal weights of the four foods occupy different amounts of space. Lesson 16, the culminating activity, challenges students to use the equal-arm balance to find out which of five containers holds a certain number of of marbles. Solving this problem requires students to apply the various comparing and weighing strategies they have used throughout the unit and provides an embedded assessment of their progress. The activities in this unit build on students' previous experiences with balance and weight and their intuitive understanding of this relationship. Through hands-on investigations and class discussions, students will not only find answers to many of their questions but also come up with new questions about balancing and weighing.
Additional assessments provide further questions and challenges for evaluating student progress.