Which Sch A and B are you referring to? Sch A on a 1040 is typically the itemized deductions like medical expenses, charity, real estate taxes mortgage interest and would calculate as a deduction to your adjusted gross income to arrive at your taxable income. I believe you are referring to For IT 225 ,NY addition and subtractions modifications, see HERE https://www.tax.ny.gov/pdf/current_forms/it/it225_fill_in.pdf.To figure out exactly where these numbers flow from Part