You are absolutely right. When adding numbers with large magnitudes differences (around 10^17 I think) it might exceed the format precision. I should have take

You are absolutely right. When adding numbers with large magnitudes differences (around 10^17 I think) it might exceed the format precision. I should have taken that in account when defining the error boundaries. In dollars, you start having issues with cents when working with a tens of trillions. For the vast majority of people this won't be an issue.