When a number is to be rounded either to an integer value or to a set number of decimal places, there will be the small amount at the end.
For example, 5.727901 = 5.73 for the purposes of a sale. This means that the delta amount is 0.002099. These amounts are still to be accounted for therefor this is sent from Revel to QBO. To find Rounding Delta in Revel please go to Reports > Operations and it can be found at the bottom of that report.
Revel sends Rounding Deltas to Rounding Deltas in QBO and this will come over as a line item on the Sales Summary Invoice for the day that gets pushed from Revel to QBO. This can be seen in the QBO integration mapping on Revel URL. To view this go to Settings > QuickBooks > Setup QuickBooks Online > Advanced View.