TT is asking me to annualize my "Other Taxes" to/for "Form 2210 Schedule AI Other Taxes". It gives me a total ($828), but doesn't tell me where that came from. Help?

Look at your Schedule 2, Part II, Other Taxes.

Or, look at Form 1040, Line 23, for Other Taxes, including Self Employment Tax. 

Thanks.  I was able to find it in Schedule 2, and traced it from there to Form 8960, where it derived from line 17 "net investment tax for individuals".

The real problem is that there seems to be no way to track this information down until *after* I filed my return and TT generated a .pdf file for me to search in.  It seems to me that what TT needs on *every* page of its questionnaire is a link to take the customer to the source of the number that TT is asking about.  Instead of being asked "How do you want to allocate this $828?", the question should be "How do you want to allocate this $828 that resulted from the calculation of these specific amounts that you entered here (link) earlier in the questionnaire".  TT is much too much of a black box in this regard.