Line 16 is not Total Tax. It's just Tax, based on the income on line 15. Other taxes get added below that. Total tax is on line 24.
On the Tax Smart Worksheet, below line A there are 7 check boxes. The one that is checked indicates what worksheet was used to calculate the tax. But if box 1 or 2 is checked, there is no worksheet in TurboTax. It just uses the Tax Table or Tax Computation Worksheet in the IRS instructions for Form 1040.
The calculation that you are using, $2,200 + 12% of the amount over $22,000, is from the Tax Rate Schedules in the IRS instructions. The "Caution" at the top of that page tells you not to use it to calculate your tax. The check box below line A of the Tax Smart Worksheet shows you the method that has to be used to calculate your tax.
You didn't say how much the difference is between your calculation and what TurboTax calculated. If the difference is small, since your taxable income is less than $100,000 you probably have to use the Tax Table (box 1 on the Tax Smart Worksheet). The Tax Table is based on $50 increments of taxable income. All incomes in a particular $50 range have the same amount of tax, so there can be a variance of a few dollars from an exact percentage.
If the difference is more than a few dollars, it's probably because you have qualified dividends or long-term capital gains, which are included in the taxable income on line 15 but are taxed at lower rates. In that case, the tax calculation is probably done on either the Schedule D Tax Worksheet or the Qualified Dividends and Capital Gain Tax Worksheet (box 3 or box 4 on the Tax Smart Worksheet).
