I was wondering if there was a way to replace a certain digit on the TI83 calculator without having to clear the whole thing and start over.

For example:

123345 if i wanted to insert a 6 for the two's spot how would i do this?

Probably not.

I don't have that kind of a calculator. On my HP, there is a <- button that removes numerical entries one at a time from the right end of the display, provided the entire number has not been "entered". If the number has already been entered and you press <-, the entire number is removed from the screen.

If you have lost the instruction manual, you can download directions for your calculator at
http://education.ti.com/educationportal/sites/US/productDetail/us_ti83p.html?bid=6

On the TI-83 calculator, you can replace a certain digit without clearing the whole thing and starting over by using the "Store" feature. Here's how you can accomplish this:

1. Press the [MODE] button to enter the MODE menu.
2. Use the arrow keys to navigate to "EDIT" and press [ENTER] to select it. This will enable the calculator to go into "Edit" mode.
3. Enter the number you want to modify, in this case, 123345. Press [ENTER] to store the number in the calculator's memory.
4. Use the arrow keys to navigate to the digit you want to replace, in this case, the two's spot (the digit 2, which is located between the first and third digits).
5. Press the [STO>] button, which is located above the [ON] button.
6. Enter the new digit you want to replace with, in this case, 6.
7. Press [ENTER] to store the modified number in the calculator's memory.

After following these steps, the calculator should display the new number with the replaced digit. In this example, it would be 126345.