IRS 85% Social Security difference

I was looking at my account online at the IRS and noticed they have the right total Social Security $20,249 and the taxable on my return is 17,212.    BUT the next line the IRS adjusted by computer is 17,211.  It's only $1 but Turbo Tax must be rounding it different?  Could that make a difference for someone?  

 

Actual amount is $20,248.80 which is 85%  $17,211.65.  Turbo Tax rounded up and IRS rounded down or drops the cents?