Compare and Order Masses

Have student pairs complete the Analyze Masses page in the Student Activity Book. Upon completion, invite students to share their responses with the class. Record some of their responses on a display to show ways of explaining why Question 1, which block has more mass, cannot be answered. For example:

• We cannot compare the masses unless we know what the blocks are made from.
• We don’t know if the blocks are solid or hollow.

For Question 2, student pairs discuss what they learned in the lesson. Use the display of Analyze Masses to summarize the observations made by students. For example:

• Larger objects do not always have more mass.
• Smaller objects do not always have less mass.
• Same-size objects do not always have the same mass.
• An object’s mass depends on its material, size, and shape.
• A two-pan balance can tell you which object has more mass if they are the same size and shape.