12.1 airbnb may , in its sole discretion , round up or round down amounts that are payable from or to guests or hosts to the nearest whole functional base unit in which the currency is denominated -lrb- i.e. to the nearest dollar , euro or other supported currency -rrb- ; for example , airbnb will round up an amount of $ 101.50 to $ 102.00 , and round down an amount of $ 101.49 to $ 101.00 .