My TI-86 answers every problem with an E answer. example: 3*3=9E0 How do I make it stop doing this? This has always been a great calc till it started doing this.

Hi,
It is still a great calculator and what it is doing now is not the result of a defect. Rather, it is a configuration setting that someone has activated.
The calculator has three display modes for the numbers.
Standard 'normal', scientific and engineering. The calculator respects the user's choice as long as possible, but if the numbers are too small or two large it uses the scientific display format.
To set the 'normal' display format:

1. Press [2nd][MODE]. On first line of screen that is displayed, make sure that Normal is highlighted. If it si not, use the arrow to move cursor on it and press [ENTER].
2. Use arrow to move cursor to 2nd line. Highlight the number of decimal digits you want (0, 1, 2, ...,or 9) and press ENTER.
3. Quit the MODE setting. From now on the calculator will use the 'normal' display format with the number of decimal digits you chose, until you change this setting again.
4. However if the number displayed is too small or too large it will be display it in scientific exponential notation. Subsequent numbers that are not too small nor too large will obey the 'normal' format.