The real value of the graphing calculator as an instructional tool is that it helps reinforce the idea that mathematics attempts to represent or describe relationships in multiple ways - using words, pictures, tables, graphs, or symbols.

We'll have a quick look at the basic button layout and what's behind some of the important buttons.

• For openers, let's describe the button layout as (almost) a 10 by 5 matrix, so we can identify where to look as an ordered pair, (row, column).
• TI refers to the top row as the graphing keys, the second and third rows as editing keys, the fourth row as the "advanced functions" keys, and below that is a more or less standard scientific calculator key, with digits, operations and special functions.
• Note the yellow "2nd" button controls the yellow functions listed above other buttons, and the blue-green "ALPHA" button controls the blue-green alpha symbols listed above the other buttons. For example, see that "OFF" is 2nd-ON.
• Take a moment to survey the menus under each of the graphing keys, and note how to navigate choices. You might also type out your name as First initial, space, Last name. Purposely make a mistake and correct it with DELETE and INSERT.
• Key in "2 + 3" and ENTER; then do 2nd-ENTRY and "* 4 x²" and ENTER. Is the answer what you expected by standard PEMDAS?
• To make sure things are set up properly for our work, press MODE and make sure that each line is "blackened" or highlighted on the left-most item; check this also for 2nd-FORMAT.
• Another important feature is 2nd-CATALOG. This allows you to find a feature from an alphabetized list instead of hunting through menus and submenus. You can scroll through the alphabetized list, or jump by entering ALPHA-[lead letter]. Some items are available only from CATALOG. In the catalog list, find and press "DiagnosticOn".

OK, we are ready to "engage". You will be guided through a set of introductory explorations that will show how the calculator can help expose mathematical thinking.

• The Thermometer Cricket
  
  
• The Car Rental Decision
  
  
• The Classic Coke Can Problem
  
  
• How Fast Is India's Population Growing?

Of course, there is much more that can be done with the graphing calculator. We hope these examples provided a good background and generated motivation for further exploration.