Here is a link to the Simplified Method Worksheet for pensions and annuities from the IRS.
If you are using TurboTax CD/Download this can be found in Premier and higher versions by using Forms mode. Look for Form 1099-R and accompanying worksheets.
If you are using TurboTax Online, there is no forms function and the only way to see the worksheets is to pay for TurboTax, then print the return as a pdf and look through the pdf to find the worksheet that you want to see.