I'm trying to figure out how Verizon has calculated their net income, I believe it should be: net income=total revenue - total costs
However, when I look at Verizon's 2020 income statement from Yahoo finance, it's not clear how they calculate net income, even if I add taxes to total expenses and subtract it from the total revenue, I still don't get the same figure for net income (17,801). I'm struggling to work out which numbers are being used in their calculations (admittedly I'm relatively new to income statement analysis).