It is the amount of state (and local) income tax withheld from your income (such as a W-2) (or the amount of sales tax that you entered) plus Property Taxes paid.
Is the negative number showing the amount UNDER the 10,000 limit?
You can look at Schedule A line 5e, but to view this you may need to switch to Itemized Deductions.
HERE is how to View your 1040 using TurboTax Online
Desktop users switch to Forms (Top right)
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