You can choose how to round off room totals in bookings. We recommend that you use two decimals, but in some situations, you might want to use 5 decimals. Go to Settings -> Sirvoy account -> Localization and choose whether to use 2 or 5 decimal places when room rates are saved in bookings.
For example, when a guest books 3 nights with different rates (80 + 80 + 85), you will get different results depending on how the average rate is rounded when saved. If the average rate is saved with five decimals (81.66667), the rounded total price will be 245.00. However, if the average rate is saved with only two decimal places (81.67), the rounded total price will be 245.01.
(Future updates will fix this issue, by saving the rate for each night, not an average rate.)