The TI-83 calculator, made by Texas Instruments, is more than your basic calculator. Not only does it perform calculations and create graphs, but you can write messages on it, too. Although you might not necessarily care about proper punctuation when writing messages or notes, you may want to add the "coma" symbol in your numbers to help you read them easier. Adding the comma isn't difficult to do, and it's simple to add a forgotten comma too.
Turn your TI-83 calculator "ON" by pressing the button on the bottom left of the calculator.
Press "Clear", which is located along the right side near the middle of the calculator, two buttons above the "÷" symbol. Pressing "Clear" removes any information previously left on the calculator.
Type the numbers or letter you wish to have the coma. For example, to type the number "7,654" press the "7" button, the "comma" button, located just above the "7" key, then press "6," "5" and "4" like normal.
Insert a comma into a number already typed by using the left or right arrow keys, located near the top right of the calculator, to get to the correct placement. Press the "2nd" button, which is the bright yellow button on the left side of the calculator, then the "DEL" button located next to the left arrow. Press the "comma" button to insert the comma.
Delete an incorrectly placed comma by moving the cursor to the correct spot and pressing "DEL" which is located next to the left arrow key.