Unable to enter tuition paid shown on form 1098-T

Go through the entire education interview until you reach a screen titled "Your Education Expenses Summary".  Click edit next to the student's name. That should take you to a screen “Here’s your Education Summary”. Click edit next to the section you want to change; tuition, in your case.

Details:

To enter your Form 1098-T information (even when TurboTax thinks it has already been entered and is showing $0), go through the entire education expenses section of your return until you reach the screen titled “Your Education Expenses Summary”, then follow these steps:

• Click Edit next to the student name.
• On the screen titled “Here’s your Education Summary”, click Edit beside Tuition.
• Enter the information from your Form 1098-T.

To go directly to the Education section of your return, use these steps:

• On the top row of the TurboTax online screen, click on Search (or for CD/downloaded TurboTax locate the search box in the upper right corner)
• This opens a box where you can type in “education” (be sure to enter exactly as shown here) and click the magnifying glass (or for CD/downloaded TurboTax, click Find)
• The search results will give you an option to “Jump to education”
• Click on the blue “Jump to education” link

Also see: https://ttlc.intuit.com/community/entering-importing/help/how-do-i-enter-form-1098-t/00/26336