The perfect sequel to Measuring Length: continue the study of area, volume and mass, and the metric units that measure them. Build metric models that help you visualize the number of stars in the Milky Way. Improvise a sensitive balance to verify that a cubic centimeter holds 1 mL of water and has a mass of 1 gram. By extension, 1000 mL (one liter) has a mass of 1000 grams (one kilogram) or 2.2 pounds. Estimate rice grains by area, volume and mass.