Originally Posted by Efrem
You weren't entirely wrong. If you use the formulas instead of the tables, you were correct. If your taxable income comes out near the bottom of a table bracket, as cordelli's must have been, using the formulas will often save a few $$.(If your income is high enough, you have to use the formulas. The tables only go up so far.)
IIRC, if your taxable income falls within the range covered by the tables, the IRS instructions require that you use the tax printed in the tables.
Edited to add: Some personal experience here: about 15 years ago I tried using the formula tax calculations when it yielded a slightly lower tax than the tables, since I ended up in the lower portion of a table bracket. I received a notice from the IRS that my refund had been adjusted by a few dollars to correct the tax to that shown in the table.