TurboTax carries at least 6 decimal places internally, perhaps as a floating-point number with many more places than that, but only displays 5 digits following the decimal point on line 10. This means that the number calculated on line 11 or line 12 might not be exactly the amount displayed on line 10 times the amount on line 8 or line 7, respectively. This is unfortunate, since the calculation might not quite make sense just looking at the numbers on the form.
What TurboTax should be doing is rounding the internal value to the value being displayed on line 10 before multiplying to get the values on line 11 and line 12.
