# Activities

• • • ##### Subject Area

• Math: Algebra I: Linear Functions

• ##### Author 6-8

60 Minutes

• ##### Device
• TI-73 Explorer™
• ##### Other Materials
This is Activity 6 from the EXPLORATIONS Book:
Activities for Algebra with the TI-73.

The following materials are required for this activity:
• Balance
• Pennies (25 pre-1982 and 25 post-1984)

You're So Dense

#### Activity Overview

Students' investigate the relationship between density of an object, its mass and its volume. They use mass and volume measurements to determine the density of pennies. They compare the density of pre-1982 and post-1984 pennies.

#### Before the Activity

• Set up the calculator for data collection using the procedure described in the attached Appendix PDF file
• See the attached PDF file for detailed instructions for this activity
• Print pages 73 - 83 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

• Fill a 50 ml graduated cylinder with water to the 20 ml mark and measure its mass
• Add 5 pennies (pre-1982) to the cylinder, record the mass, and note the volume
• Repeat the step, adding batches of 5 pennies (until 25 pennies have been added); record the mass and volume after each addition
• Calculate the density of the pennies
• Repeat the activity with 25 post-1984 pennies
• Calculate the density of the pennies
• Compare the density data
• Measure the volume and density of another set of 15 pennies
• Use the data to determine the density and categorize the pennies
• Given the mass of the pennies, predict the volume
• Given the volume of the pennies, predict their mass
• #### After the Activity

Students' will complete the Data Collection and Analysis page and answer questions.

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary