# Activities

• • • ##### Subject Area

• Math: Middle Grades Math: Number Sense
• Math: Middle Grades Math: Basic Facts
• Math: PreAlgebra: Number Sense and Operations

• ##### Author 6-8

30 Minutes

• ##### Device
• TI-73 Explorer™

## Constants

#### Activity Overview

Students use the calculator to determine the amount of money that will accumulate in a savings account, if every month a certain sum is deposited in the account. They explore the use of the constant function key on the calculator to make repeated additions.

#### Before the Activity

• Set up the calculator as explained in the appendix file
• See the attached activity PDF file for detailed instructions for this activity
• Print the pages from the attached activity PDF file for the class
• #### During the Activity

Distribute the pages to the class.

• On the calculator, enter as a constant, the operation of addition and the amount deposited every month
• Note the first entry represents the first deposit for the first month
• Press the constant key to repeat the process of adding the monthly deposit and find the amount accumulated in the savings account after two months
• Observe that the accumulated amount and the amount added in each step is displayed on the screen
• Find the balance that will accumulate after different time periods, by using the constant key