Are the instructions for calculating the taxable portion of the state tax refund correct? Referencing non-existent lines on 2018 1040 (line 40, 44, 56, etc)?

I am trying to manually perform these calculations as directed by TurboTax, however, I am losing confidence because I can't find the relevant lines on the 2018 forms as instructed. Best I can tell they were on the 2017 1040.