Why is the state and local taxes greater than $10,000.00 a negative number on my deductions summary

[KrisD · Accepted solution]

Because of the Tax Cuts and Jobs Act, this year only 10,000 of state tax is deductible on the federal return. 

The negative number is just to recognize that you entered more than 10,000, so the excess is not computed on the Federal return; however it is not deducted from the 10,000 that is allowed.